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PSYCHOLOGY 



PSYCHOLOGY 



BY 

BURTIS BURR BREESE 

PROFESSOR OF PSYCHOLOGY IN THE UNIVERSITY OF CINCINNATI 



ILLUSTRATED 



CHARLES SCRIBNER'S SONS 

NEW YORK CHICAGO BOSTON 



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Copyright, 1917, by 
CHARLES SCRIBNER'S SONS 



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PREFACE 

The present text aims to give a comprehensive view of 
the facts, principles, and theories of human psychology. 
Accordingly, the student will find that it represents 'the 
various points of view of modern psychology — the analytic 
and the descriptive, the structural and the functional, the 
genetic and the physiological. At the same time the em- 
pirical results of experimental psychology are used as far as 
possible. Thus at the beginning the student is given a broader 
foundation for the understanding of mental life than could 
be given by a more limited point of view. 

From the very outset an attempt has been made to dif- 
ferentiate the metaphysical and the empirical tendencies in 
psychology. It is important that the student should know 
when he is indulging in naive metaphysical speculation, and 
when he is dealing with the results of scientific observation 
or the theories based upon such observation. 

While I am in sympathy with the present attempt now 
being made in some quarters to emphasize the objective and 
quantitative aspects of consciousness, nevertheless I confess 
the beHef that the quahtative aspect is still worthy of psycho- 
logical consideration, and that, in order to get at this quahta- 
tive aspect, the method of introspection is still a valid method 
of psychological procedure. 

I am very much indebted to Mr. Schachne Isaacs, In- 
structor in Psychology, University of Cincinnati, for prepar- 
ing the index, for reading the manuscript and proofs, and 
for many helpful suggestions in the preparation of the text. 

Acknowledgments are due for the use of illustrations 
taken from the following text-books: Villiger's "Brain and 
Spinal Cord," J. B. Lippincott Co.; Quain's "Elements 



VI PREFACE 

of Anatomy," Longmans, Green and Co.; Angell's "Psychol- 
ogy," Henry Holt and Company; Howell's "Text-Book of 
Physiology," W. B. Saunders and Company; Pillsbury's 
"Essentials of Psychology" and Titchener's "Text-Book of 
Psychology," The Macmillan Company; Thorndike's "El- 
ements of Psychology"; Ladd and Woodworth's "Physio- 
logical Psychology" and Judd's "Psychology," Charles Scrib- 
ner's Sons. 

B. B. B. 

University of Cincinnati, 
June, 191 7, 



CONTENTS 



I. Introductory 

Divisions of Psychology. The Procedure of Psychology. 
Consciousness. Subject-Object Nature of Consciousness. 
Soul. Mind. Self. 

II. The Nervous System 



Consciousness and the Nervous System. The Gross Struc- 
ture of the Brain. The Autonomic Nervous System. Nerve- 
Cells. Nature of the Nervous Impulse. Kinds of Neurones. 
White and Gray Matter. The Fibre Connections of the 
Brain. Localization of Function. 

III. Attention 53 

Forms of Attention. Neural Basis of Attention. Shifting of 
Attention. Range or Span of Attention. Effect of Atten- 
tion. Motor Accompaniments of Attention. Feeling of 
Effort in Attention. Interest and Attention. 

IV. Sensation 87 

Sensation as an Element of Consciousness. Pure Sensations. 
Physiological Basis of Sensation. The Nature of the Nerve- 
Impulse. Evolution of Sense-Organs. The Stimuli. After- 
Effects of Stimulus. Sensory Adaptation. Attributes of 
Sensation. Quality. Intensity. Extensity. Duration. 
Other Attributes. Kinds of Sensations. 

V. Organic, Kinesthetic, and Cutaneous Sensa- 
tions no 

Organic Sensations. Kinsesthetic Sensations: Muscle, Ten- 
don, and Joint Sensations; Sensations from Vestibule and 
Semicircular Canals. Cutaneous Sensations: the End- 
Organs; the Brain Centres; Pressure-Sensations; Pain- 
Sensation; Sensations of Cold and Warmth. 



Vlll CONTENTS 

CHAPTER PAGE 

VI. Olfactory and Gustatory Sensations . . . 130 

Olfactory Sensations: End-Organ; the Stimulus; Classifica- 
tion. Gustatory Sensations: End-Organ; Gustatory Nerves 
and Brain Centres; Stimulus; Classification of Gustatory 
Sensations; Retardation; Mixtures, Contrasts, Adaptation; 
Threshold; Complexes. 

VII. Auditory Sensations 144 

End-Organ. Brain Centres. The Stimulus. Noises. Tones. 
Compound Tones. Timbre. Beats. Combination Tones. 
Intensity. Extensity. Musical Tones, Consonance, and 
Dissonance. 

VIII. Visual Sensations 166 

The Retina. The Optic Nerve and Optic Centres. Stimulus. 
Kinds of Visual Sensations. Brightness of Colors. Purkinje 
Phenomenon. Saturation. Complementary Colors. The 
Color Pyramid. Color Mixtures. Light and Color Adapta- 
tion. Successive Contrasts. Simultaneous Contrasts. Color 
Zones of the Retina. Color-Blindness. Color Theories. 
The Young-Helmholtz Theory. Hering Theory. Ladd- 
Franklin Theory. 

IX. Perception 197 

Perception of Objects. Complication. Recognition. Mean- 
ing. Illusions. Hallucinations. Perception of Space: De- 
velopment of Space Perception; Third Dimension; Space 
Errors and Illusions; Localization and Projection of Audi- 
tory Sensations. Perception of Time: Elements of Time Per- 
ception; the Psychical Present; Sensory Material of Time 
Perceptions; the Psychical Present and the Logical Present; 
the Past and the Future; the Measure of Time. 

X. Memory 238 

The Image. Definition of Memory. Organic Memory. In- 
dividual Differences in Memory. The Training of the Mem- 
ory. Methods of Memorizing. Forgetting. Defects of 
Memory. Function of Mem^ory. 

XI. Imagination 260 

Memory and Imagination. Kinds of Imagination. Repro- 
ductive Imagination. Productive Imagination. Types of 
Imagination. VisualType. Auditory Type. Motor Type. 



CONTENTS IX 



Mixed Types. Methods of Determining the Types of Im- 
agination. Imagery in Synaesthesia. Concrete and Symbolic 
Imagination. Image and Idea. Training of Imagination. 
Imagination as a Means of Supplementing the Present. 
Imagination and Behavior. 

XII. Association 277 

Formation of Associations. Motor Connections. Mental 
Connections. Associative Recall. The Laws of Associa- 
tion. Contiguity. Similarity. Partial and Total Recall. 
Falsification of Association. Association Tests. Physio- 
logical Basis of Association. 

XIII. Conception 299 

Thinking. The Concept. The Formation of the Concept. 
The Psychological and the Scientific Concepts. The Gen- 
eral and the Individual Concept. The Analysis of the Con- 
cept. The Image. Consciousness of Meaning. The Inten- 
sion and Extension of Concepts. The Genesis and Develop- 
ment of the Concept. Language. Origin of Language. 
Thought and Language. 

XIV. Judgment . 321 

Judgment and Perception. The Nature of Judgment. Judg- 
ment as Apperception. Judgment as Belief. Judgment as 
the Ascription of Meaning. Judgment as Comparison. 
Judgment as Evaluation. Kinds of Judgments. Analysis 
and Synthesis. Judgment and Concept. Judgment as the 
Fundamental Cognitive Activity. 

XV. Reasoning 338 

Inference. Inference and Perception. Inference and Judg- 
ment. Inference and Concept. The Nature of Reflective 
Thought, or Reasoning. The Steps in Thinking. Kinds 
of Reasoning. Reasoning and the Syllogism. Imageless 
Thought. The Neural Basis of Reason. 

XVI. Affection and Feeling . 356 

Affection. The Nature of Affection. Kinds of Affection. 
Attributes of Affection. Adaptation. Affection and Sensa- 
tion. Pain and Affection. Affection and Perception. Af- 
fection and the Ideational Processes. .Affection and Bodily 
Expressions. Neural Basis of Affection. The Significance 



X CONTENTS 

CHAPTER PAGE 

and Function of Affection. Feeling. Classification of 
Feelings. Mood. Temperament. Emotions. Sentiments. 
Passion. 

XVII. Emotions 377 

James-Lange Theory of Emotions. The Instinctive Reac- 
tions and Emotions. Conditions Which Give Rise to Emo- 
tions. Significance of Emotions. Classification of the Emo- 
tions. Emotions and Memory. 

XVIII. Consciousness and Behavior 397 

Volitional Action. Genesis of Motor Activity. The Connec- 
tion between Conscious States and Action. The Law of 
Dynamogenesis. Control. Effect of Motor Activity upon 
Consciousness. 

XIX. Will 419 

Conation. Will. Will as Self-Determination. Will and 
Knowledge. Will and Character. Freedom of the Will. 

XX. The Self . . ' . 432 

The Unity, Continuity, and Identity of Personal Conscious- 
ness. The Subject Self, or Ego. The Empirical Self. Origin 
and Growth of the Self. Contents of the Self. Conscious- 
ness of the Self. Self and Sensation. Self and Perception. 
Self and Attention. Self and Interest. Self and Feeling. 
Self and Will. Sleep and the Self. Dreams and the Self. 
Disturbances of the Self. Mental or Psychic Blindness. 
Automatic Writing. Somnambulism. Hypnosis. Double 
Personality. Insanity. 

Bibliography . . . . . . . . ... . 463 

Index 471 



PSYCHOLOGY 



PSYCHOLOGY 

CHAPTER I 
INTRODUCTORY 

Psychology is that study whose task it is to point out 
and organize the observable facts of conscious life, and to 
formulate the theories, or hypotheses, necessary to explain 
these facts. In this study it is important that the student 
should distinguish clearly between fact and hypothesis — be- 
tween what is obtained through scientific observation and 
what is logically constructed through speculation. Psychol- 
ogy was in its earliest stages a branch of philosophy, and was 
more inclined to speculate about the nature of consciousness 
than to observe and systematize the facts connected with it. 
This is illustrated in the attempts to explain consciousness in 
terms of the soul, a metaphysical being beyond actual obser- 
vation. Modern psychology concerns itself more with the 
facts and less with the ultimate nature of consciousness. 

If we consider all the facts which come from actual ob- 
servation we may put them into three groups: 

1. Facts about matter. 

2. Facts about life. 

3. Facts about consciousness. 

The first group forms the subject-matter of the material sci- 
ences; the second group forms the subject-matter of the bio- 
logical sciences; and the third group forms the subject-matter 
of psychology. 

Divisions of Psychology. — There are a number of special 
forms of psychology determined by the fields of mental life 



2 PSYCHOLOGY 

from which the psychologist draws his material, and by the 
methods and points of view he employs in his study. With 
respect to the fields of consciousness we have: 

1. Adult human psychology. 

2. Child psychology. 

3. Social psychology. 

4. Abnormal psychology. 

5. Animal psychology. 

With respect to methods and special points of view we 
have : 

1. Descriptive psychology. 

2. Experimental psychology. 

3. Genetic psychology. 

4. Functional psychology. 

5. Physiological psychology. 

6. Psychophysics. 

7. Comparative psychology. 

Adult Human Psychology considers the consciousness found 
in the adult human being. It points out the common quali- 
ties, processes, and modes of activity found in human beings 
generally. Since individuals differ from each other in men- 
tal characteristics, a study of these differences is also impor- 
tant. This study has been termed individual psychology. 

Child Psychology deals with the conscious states of the 
child. It takes account of the stages of mental development 
through which the child passes. Since the genesis of con- 
sciousness is important here, child psychology is a part of 
genetic psychology; and since a large part of the child's Hfe 
is spent in school under a formal educational system, child 
psychology and genetic psychology often take the form of 
educational psychology. 

Social Psychology has to do with conscious experiences 
which are made possible by the presence of an individual 
mind in a group of other minds. Such experiences are due to 
what has been termed social consciousness. Out of it spring 
language, laws and customs, myths and religion — all of which 



INTRODUCTORY 3 

are dependent upon the existence of a community of individ- 
uals. The use of the terms "social consciousness" and "col- 
lective mind" must not be understood to indicate the assump- 
tion of the existence of another kind of consciousness other 
than that found in individuals. These terms refer only to 
the conscious states in individuals which are due to a com- 
munity of minds. Communities of people have the same 
language, customs and fashions, religion and mythology. 
The conscious experiences back of these institutions we as- 
sume to be the same in all individuals. Since much of our 
mental life is social, social psychology overlaps normal adult 
psychology and draws its material from it. A subdivision of 
social psychology, variously named as race psychology, ethnic 
psychology, or folk psychology, is interested in the mental 
characteristics of different races or peoples. It may include 
the comparison of the mental traits found in different peoples. 
We may compare the Japanese, on the one hand, with the 
Russians on the other; or the primitive races, like the Ameri- 
can Indians or Malays, with the more civilized races. A still 
further subdivision might take up the study of classes, pro- 
fessions, and occupations. 

Abnormal Psychology deals with abnormal mental states, 
such as hypnotism, double or multiple personahty, fixed 
ideas, hysterias, mania, melancholia, dementia, paranoia, 
idiocy. Here also should be included the study of deficient 
and exceptional minds — the weak-minded and the genius. 
The criminal mind belongs in this list, because most criminals 
are abnormal. 

Animal Psychology takes as its subject-matter the mental 
states of animals. The absence of language in animals limits 
the possibilities of studying the consciousness which we know 
exists there. Man can describe his experience in language, 
but animals cannot. However, the behavior of the animal 
is a clew to the kinds of consciousness it has. We may 
therefore study its behavior and so, indirectly, its conscious- 
ness. Since we may proceed from the lowest animal forms 



4 PSYCHOLOGY 

to the highest, animal psychology may be genetic in its point 
of view. 

Descriptive Psychology is really a method of studying con- 
sciousness. It analyzes, describes, and classifies conscious 
experiences. 

Experimental Psychology is laboratory psychology. Lab- 
oratory methods and physical apparatus are used as means 
of controlling and studying mental states. Of course, the 
psychologist cannot measure or weigh the conscious states of 
his subjects. He cannot even observe them directly. He 
may, however, measure the time during which a conscious 
state exists. He may measure or weigh the physical stimuli 
and correlate the results with the intensities of the conscious 
experiences. He may also note the physiological changes 
which take place in the body while the conscious states are 
going on. For all this he uses instruments of precision, but 
nowhere in his laboratory has he an instrument that will 
measure a mental state itself. A large part of this study de- 
pends upon the introspective report given by the subject. 

Genetic Psychology considers the successive stages of men- 
tal growth and the evolution in the individual and in the 
race. We may use a pair of terms that are common to biol- 
ogy and psychology to designate the two lines of development 
— phylogenesis, or racial development, and ontogenesis, or indi- 
vidual development. These terms really refer to the growth 
and development of organisms as a whole — both mind and 
body. Mental development in phylogenesis includes all the 
stages of conscious life which appear in the evolution of ani- 
mal forms from the lowest to the highest. These stages of 
development may be considered either as a series now exist- 
ing, or as a series constituting the successive stages of evolu- 
tion from the earliest time to the present. Mental develop- 
ment in ontogenesis includes the stages of development which 
take place in an individual from birth to death. The biolo- 
gist finds a relation between ontogenesis and phylogenesis 
which he states as the principle of recapitulation. According 



INTRODUCTORY 5 

to this principle, the individual in embryo passes through the 
same stages of development that the race has passed through. 
Thus, biological recapitulation suggests a problem for genetic 
psychology: Does the child in his mental development pass 
through the stages of mental development that the race has 
passed through ? ^ The chief problem of genetic psychology, 
however, is that of making out the stages of mental develop- 
ment of the individual. 

Functional Psychology looks upon consciousness as a 
process. Formerly the mind was supposed to possess the 
functions of knowing and willing. Later a third function, 
that of feeling, was added. Knowing, feeling, and willing are, 
from the point of view of functional psychology, the functions 
of the mind. A more recent functional point of view asserts 
the presence in the mind of a purposive factor which deter- 
mines the direction and nature of conscious processes. While 
external conditions (stimuli) do this to a certain extent, it is 
claimed that these factors are not sufficient to explain con- 
scious activity adequately. A conscious agency, therefore, is 
assumed to account for the character of our conscious states. 

Physiological Psychology considers consciousness as either 
the direct outcome or the correlate of brain activity. Physio- 
logical psychology does not, however, necessarily commit 
itself to a materialistic philosophy. For consciousness may 
be non-material or spiritual in its nature and yet be depen- 
dent upon the brain for an opportunity to manifest itself. 
The brain may be only the medium or agent for conscious- 
ness and not its real cause. But whether its philosophy is 
materialistic or spiritual, it bases its particular point of view 
and its method upon the observable fact of correlations be- 
tween consciousness and nervous processes in the brain. It 
accordingly takes the activity of the nervous tissue as its 
starting-point, acquaints itself with the facts of the anatomy, 
histology, and physiology of the nervous system, and at- 

'For a discussion of this question the student is referred to "Mental De- 
velopment in the Child and the Race," by James Mark Baldwin. 



6 PSYCHOLOGY 

tempts to find out what happens in the brain when we are 
conscious, or, more exactly, to find out what the correlations 
are between the nervous activities on the one hand and men- 
tal states or activities on the other. It really combines a 
large part of neurology (that which has to do with the higher 
brain centres and their connections) with psychology proper. 
One of its important problems is the localization of brain 
centres for the different conscious processes. For example, 
it finds the centre for sight in the occipital lobes of the brain, 
the centre for hearing in the superior convolution of the tem- 
poral lobes, and so on. In the present state of knowledge of 
the physiology of the nervous tissue there is relatively little 
known concerning the nervous action in the brain. At the 
present time, then, physiological psychology can be little 
more than the statement of a series of neurological facts on 
the one hand, and of conscious facts on the other. 

Psychophysics is the study of the relations which exist 
between consciousness and the world of physical objects 
which are capable of acting as sense-stimuli. It is a partner- 
ship between physics and psychology, and is included under 
experimental psychology as now carried on in the psychologi- 
cal laboratory. 

Comparative Psychology has taken at least two directions. 
In some quarters it has been identical with animal psychology 
and has occupied itself with the comparison of the mental 
life found in the various types of animals. This might well 
include a comparison of the mental life of the animal forms 
with that of man, but this is a problem for the future. A 
wider significance has been given in other quarters to com- 
parative psychology in that it is considered as a comparison 
of the normal human adult consciousness with that found in 
the child, in abnormal man, in social groups, and in animals 
respectively. 

The Procedure of Psychology. — Although the array of 
psychologies seems rather long and perplexing, the matter 
becomes really very simple when we remember that they are 



INTRODUCTORY 7 

all studies of consciousness, and that consciousness is found 
only in human beings and animals. Nearly all these forms 
of psychology are simply special methods, or points of view, 
used in the study of animal and human consciousness. A 
general psychology, such as we are entering upon, takes for 
its subject-matter the highest type of consciousness — that of 
the adult human being. But it may make use of any of the 
different special methods and points of view, or even of the 
subject-matter of the different psychologies, in so far as it is 
helpful in understanding the mental life of normal man. 

The fundamental method of psychology is observation: 
first, the observation of the mental states and processes tak- 
ing place in our own minds, and second, the observation of 
the behavior of others by means of which we may infer the 
presence and nature of their mental states. These two forms 
of observation are necessary in psychology. Without the 
first we could never have an intimate first-hand acquaintance 
with the facts of consciousness, and without the second we 
would know nothing of consciousness outside our own minds. 

The first form of observation gives us direct knowledge 
of our own conscious life and has been termed — introspection, 
i. e., looking within. Introspection is the observation of our 
own mental states. This self-observation does not, however, 
presuppose a new process or method of observation intro- 
duced by the psychologist. Introspection does not differ 
fundamentally from the observation employed in the other 
sciences. The difference lies only in the material upon which 
it works. Introspection in psychology is observation of men- 
tal facts, while observation in the other sciences is observa- 
tion of material facts. Introspection has sometimes been 
taken to be an inner consciousness in distinction to an outer 
consciousness which knows the outer world of objects. But 
there is no valid ground for such a distinction. All conscious- 
ness, whether it be awareness of mental states or of material 
objects, is of the same character. The distinction of inner 
and outer has no meaning when applied to consciousness it- 



8 PSYCHOLOGY 

self. The awareness of a material object is just as much 
inner consciousness as the awareness of a mental state. Both 
are contents of consciousness. The ability to introspect im- 
proves with training and practice. The novice in psychology- 
is quite as helpless as the beginning student in biology when 
given his first high-power microscope. Expertness is needed 
no less for the accurate observation of mental states than for 
the accurate observation of material specimens in biology, 
physics, or chemistry. 

Objections have been urged against introspection as a 
scientific method on the ground that its results cannot be 
verified. The claim has been made that the results of intro- 
spection cannot be confirmed because no one can observe 
directly the conscious states of another. On the other hand, 
the objects of material sciences are said to be common prop- 
erty. Any one may observe them and confirm the reports of 
others. This distinction of the private nature of consciousness 
and the public nature of objects is not as far-reaching as it 
seems at first sight. All the sciences are built up by means 
of observation. But every observation is the observation of 
some one person. The observation itself is always a private 
and personal affair. Different observations can be brought 
together and made to agree only when reduced to a common 
unit of measurement. By means of this unit of measurement 
uniformity may be established, and this is the most important 
thing in all observation. In the material sciences the uni- 
formities are found in terms of units of quantity — the milli- 
metre, the gram, et cetera. In psychology the uniformities 
are in the terms of quality — quality of experience. The units 
of quality are descriptive units, or language symbols. The 
facts of consciousness discovered by means of introspection 
may be reduced to the common terms of descriptive language. 
If when measured by these common terms the experiences of 
different observers show uniformity, that is sufficient verifi- 
cation. 

Restating this point, we may say that the so-called mate- 



INTRODUCTORY 9 

rial objects of the sciences always fall within some one's pri- 
vate experience. The material object which I observe is my 
object, and the material object which you observe is your 
object. You can never experience my object and I can never 
experience your object. They become common to both of 
us only when they are described in the same terms, i. e., re- 
duced to the same symbols. Likewise, my consciousness and 
your consciousness become common property when described 
and communicated through the medium of language. The 
reliability of these descriptions depends, of course, upon the 
degree of accuracy with which the symbols of language are 
used. There is, to be sure, greater opportunity for variation 
and error in the language description of psychical facts than 
in the quantitative units of measurement of the material 
sciences. But even in the material sciences there is variation 
and error. No two observers report exactly the same results 
from the observation of material objects. The method of in- 
trospection in psychology and the method of observation 
employed in the material sciences are alike in their funda- 
mental procedure. They both reduce the results of individ- 
ual and personal observation to the common terms of mea- 
surement or description, and by means of the uniformities 
discovered verify the facts. When a number of investigators 
co-operate and compare the results of their introspection, 
and repeat them again and again, a mass of cumulative evi- 
dence is obtained that is entirely trustworthy. 

Another objection to introspection has been offered on 
the ground that the observation of mental states cannot take 
place without changing their nature. This objection is based 
upon the assumption that the consciousness of mental states 
is not the same as the consciousness of material objects. 
This assumption, as we have seen, is not well founded. We 
have spoken of this before, but let us remind ourselves again 
that the observation of mental states is not a different kind 
of observation from that by which we know the material 
world. The physicist interprets his experience in one way 



lO PSYCHOLOGY 

and the psychologist in another, hut the interpretation is a 
construction which is put upon the experience after it is over. 
In the one case we are interested in the experience as an 
object belonging to an independent material world. In the 
other case we are interested in the experience as a part of 
our consciousness. At the moment of observation both the 
object and the mental state are given in our awareness. 

The second form of observation in the procedure of psy- 
chology supplements introspection. It is the observation 
of behavior. From these external manifestations we may 
not only infer the presence of consciousness, but its nature. 
When a man smiles we judge that he is pleased. When a 
young child cries we know that it is experiencing pain. We 
can establish the fact that there is a large number of corre- 
spondences between the two series of events. Bodily move- 
ments and attitudes are the outward signs of conscious states. 
The quiver of the eyelid, the tremor of the muscles about the 
mouth, the faint blush upon the cheek, the peculiar quaHty 
and intonation of the voice, all betray to the practised ob- 
server the nature of the conscious states back of them. In 
young children and animals observation of behavior is the 
only means we have of gaining knowledge of their mental 
states. 

Consciousness. — What consciousness ultimately is we do 
not know any more than we know what life ultimately is. 
Many theories have been formed about its real or intrinsic 
nature, but so far these theories have been of little value to 
the science of psychology.' 

When the psychologist asserts his inability to define con- 
sciousness ultimately he does not intend to imply that psy- 

' Such inquiry really belongs within the province of metaphysics and not 
in psychology. We may, however, note two opposing theories concerning the 
ultimate nature of consciousness that have been generally held: 

1. The spiritualistic hypothesis. 

2. The materialistic hypothesis. 

The spiritualistic hypothesis holds consciousness to be states of an unex- 
tended permanent being of immaterial or spiritual nature. The materialistic 



INTRODUCTORY II 

chology is different from the other sciences in respect to the 
definition of its fundamental subject-matter. No science is 
able to define its subject-matter ultimately. What matter 
really is remains as great a mystery as ever, even though the 
sciences of physics and chemistry attempt to define it vari- 
ously in terms of energy, or in terms of the atom* the ion, or 
the electron. These are metaphysical conceptions, and they 
tell us no more about the real nature of matter than the spir- 
itualistic or the materialistic hypothesis tells us about the 
real nature of consciousness. Biology, too, is unable to define 
life ultimately, although it has been tempted into metaphysi- 
cal speculation about it. This is illustrated by the attempt 
in some quarters to conceive life as a manifestation of "vital 
force" — a principle of mysterious and unfathomable essence 
thought to be the cause of life phenomena. Even the at- 
tempt to reduce life to some form of refined chemical reac- 
tion is none the less pure speculation. Just as the material 
and biological sciences have now given up speculation about 
the transcendental nature of matter and life, so psychology 
no longer speculates about the transcendental nature of con- 
sciousness. 

While we are unable to reduce consciousness to anything 
more fundamental than itself, we are able to define it as 
observable fact. When we say that we are conscious we 
mean that we have experiences that we know directly. Every 
moment of our waking lives we are conscious: we see lights 
and colors, or hear sounds, or taste foods, feel pleasures or 
pains, perceive objects, image forms, remember past events, 
or form judgments, reason, feel glad or sad, or angry, love or 
hate, resolve, decide, and experience impulses to act. Any 
or all of these are states of consciousness. We can observe 
them directly. We can analyze those that are complex into 

hypothesis regards consciousness as a form of nerve-energy which, so far, we 
have not been able to observe and measure. But whatever the metaphysical 
basis of consciousness may be, the facts of consciousness remain the same as 
far as observation of them goes. 



12 PSYCHOLOGY 

simple conscious states and can weave them into a system of 
relationships. 

Some of the earlier English psychologists used the term 
consciousness to signify awareness of one's own mental states 
and processes. Locke defined it as the "perception of what 
passes in a man's own mind," and Reed as "that immediate 
knowledge which we have of all the present operations of our 
own mind." But more recently that meaning has been dis- 
carded and now the term consciousness is used to indicate any 
and all mental experience; not only the awareness of our own 
mental states, but also awareness of objects and relations in 
the outer world; not only the mental experience of man but 
the mental experience of all sentient beings. 

Subject-Object Nature of Consciousness. — One of the 
most troublesome points to keep clear in discussing the na- 
ture of consciousness is the distinction which we are logically 
forced to make between the subject side of consciousness and 
the object, or content, side. To be conscious impHes some 
one who is conscious. To have a sensation or thought seems 
logically to involve a subject to which the sensation or thought 
is presented. What thinks the thought? What has and 
owns the sensation? Professor James's answer, "that the 
thoughts themselves are the thinkers," does not satisfy the 
logical need of our thinking. This question appears in vari 
ous forms in the study of conscious phenomena. We cannot 
attempt really to answer it without entering the field of meta- 
physics, but psychology has the right to make any assump- 
tion concerning it that is in accord with the facts of con- 
sciousness. The spiritualistic hypothesis of consciousness 
assumes a being of psychical nature, a permanent ego, or 
knower, to which all consciousness as content is presented. 
This double aspect of consciousness has given rise to two 
different points of view concerning consciousness: 

1. Consciousness as the act of the subject. 

2. Consciousness as content of experience. 

It is important for the student to keep clearly in mind 



INTRODUCTORY 1 3 

these two possible meanings of consciousness, because in psy- 
chology the term is sometimes used in one sense and some- 
times in the other, and often the meanings are confused. 
The first meaning considers only the subject and its activity 
in attending, perceiving, feeling, willing, et cetera. The sec- 
ond meaning considers only the content of experience, or, in 
common terms, that which is experienced — a sensation, a 
percept, a memory image, an emotion, et cetera. For exam- 
ple, the content of consciousness is that which is presented to 
us as different experiences. The experience of red is different 
from that of green. The experience of the taste of sugar is 
different from the experience of the sound of middle C on the 
piano. The experience of an emotion is different from the 
experience of a memory image. Such experiences make up 
the content of consciousness. 

It is not possible in an introductory psychology to avoid 
the use of consciousness as subject and consciousness as con- 
tent, but it. is possible to know when we are using the one 
and when the other. As an illustration of the two meanings 
of consciousness found in the literature of psychology we may 
instance the widely differing definitions offered for some of 
the most common concepts. For example, if the student will 
read the definitions of attention in a number of text-books on 
psychology, he will find that in some attention is defined as 
the "power of the mind to concentrate, select, and prolong 
consciousness," while in others it is defined as "clearness, 
vividness, or distinctness of mental content, accompanied 
by a complex of muscular strain and effort." It is plain that 
in the former case consciousness is conceived as a subject or 
agent manipulating the contents of its experience, while in 
the latter case consciousness is merely content. 

It is the content side of consciousness which furnishes the 
facts of scientific psychology, because the content of our ex- 
perience is the only part of consciousness that lends itself to 
observation. It is the only part about which we can have 
definite, empirical knowledge. On the other hand, the so- 



14 PSYCHOLOGY 

called subject of consciousness always lies outside the world 
of observable facts. It is a logical construction which should 
be used in psychology only as a convenient hypothesis. In 
referring to the subject of consciousness as a logical construc- 
tion, we mean that it is a factor which appears only after we 
begin to think about the facts of consciousness and attempt 
to explain them rationally. It is, therefore, a product of 
thought, and not a directly observable reality. 

Those who have attempted to avoid the hypothesis of a 
spiritualistic subject of consciousness or have denied its exis- 
tence, usually substitute for it the assumption that conscious- 
ness is really some form of nervous energy. They assert that 
there is no necessity of assuming anything more than this 
nervous energy in a living and acting brain to account for the 
phenomena of consciousness. Whether we accept the hy- 
pothesis of a psychical or spiritual subject of consciousness, 
or that of the material nature of consciousness, really makes 
little difference within psychology itself so long as we are 
consistent in holding to one or the other. The observable 
facts remain the same in either case. The sensation of red 
is just what it is experienced to be, whether it is referred to 
a psychical subject or to a form of nervous energy. If con- 
sciousness is a form of nervous energy, then the brain or 
nervous system is the unifying principle which has and owns 
the conscious states. Now, we know by actual observation 
that conscious states as content of experience exist only at 
the moment of their experience. Then, according to the 
materialistic conception, they become, when they cease to 
be experienced, merely states or conditions of the nervous 
system. They may be revived again when the nervous ma- 
terial which has given rise to them is stimulated into activity. 
This conception tacitly assumes a mode of transformation be- 
tween material brain processes and conscious experience that 
is beyond the realm of observable fact. Even if it were pos- 
sible to observe all the details of the brain-cell processes, and 
to follow them to their last chemical or physical activities, 



INTRODUCTORY 1$ 

they would still be just what they are — material processes. 
The particular manner or mode of their transformation into 
conscious states is never revealed to us as observable fact. 
The central point in this materialistic hypothesis is the asser- 
tion that conscious states are really and ultimately some form 
of nervous energy in the brain, and that therefore the brain 
is the ultimate ground of existence for all consciousness. 

The student should not confuse this assumption with the 
observable fact of the dependence of conscious phenomena 
upon the brain or nervous system in a living organism. The 
assumption attempts to explain the ultimate or real nature 
of consciousness by reducing it to nervous energy. On the 
other hand, the establishment of the fact of the dependence 
of consciousness upon the nervous system does not involve 
the question of what its ultimate ground of being is, but 
rests its case upon the observable facts of consciousness on 
the one hand, and the observable facts of brain states and 
activities on the other. 

Soul. — In popular thought it is often the soul which plays 
the part of the subject of consciousness. Here we meet the 
idea that it is the soul that knows and feels and wills. But 
the popular conception of the soul really involves so many 
transcendental and metaphysical attributes that it cannot be 
used profitably in psychology. If the term is used at all 
there, as it oftentimes is, it must be shorn of many of its 
metaphysical implications and made identical with the mere 
subject of consciousness. The old and popular meanings 
are apt, however, to associate themselves with its use, even 
in a restricted sense. So it is better to avoid the term in 
psychology.^ 

Singularly enough the term soul has sometimes been used 
to signify the content side of consciousness. This concep- 
tion makes it the sum total of one's thoughts and feelings. 
But this is altogether unjustifiable, because it twists the term 

' It is a narrow and pedantic view which for this reason denies its existence 
as an ultimate reality. 



1 6 PSYCHOLOGY 

too far from its popular and original meaning. Its use as the 
subject of consciousness is preferable, for then it retains some 
of its old meaning as a permanent being, or entity, behind our 
consciousness experiences. 

Mind. — The double aspect of consciousness appears again 
when we try to get a clear idea of what is meant by mind. 
Very commonly it is used to designate that which owns the 
conscious states. Thus we speak of a sensation, a perception, 
an image, a feeling, or an emotion as in the mind, or we may 
say that the mind has the sensation, the perception, et cetera. 
In this way we think of the mind as a continuous, if not per- 
manent, psychical being persisting through the varying states 
of consciousness and holding them together, and possessing 
powers, capacities, attributes, and dispositions which are al- 
ways in existence, even when not active. Used in this sense, 
it turns out to be the same conception as that of the subject 
or knower of consciousness, and it is therefore metaphysical 
in its real meaning. In this sense the mind is that something 
that knows and feels and wills, but what that something is, 
is never given to us as an observable fact. 

On the content side of consciousness mind is the sum total 
of all our mental states. Sensations, images, memories, judg- 
ments, feelings, desires, volitions, et cetera — all these organ- 
ized, systematized, and unified in such a way that they hang 
together as an individual whole. This is the mind that we 
know directly. Since, however, the content of experience is 
known only in the present moment, and since each present- 
moment experience is in a way separate from all others, we 
might think at first glance that there could be no unity or 
organization in the contents of experience themselves, and 
that without a unifying subject the contents of consciousness 
would remain a mere series of isolated bits, strung out in a 
time sequence. In fact we very frequently find references 
to the subject of consciousness as that something, the sole 
function of which is to organize the various elements of our 
experience into some sort of unity. Without this something 



INTRODUCTORY I 7 

it is claimed that no organization or unity can exist. But 
the present moments of experience do contain actual and 
observable material which binds them together. For in- 
stance, if I recognize a man to-day whom I met last week, the 
present moment of consciousness has in it not only the pres- 
entation of the man to-day, but the memory of the man last 
week. Thus the present-moment experience has in it as a 
part of its content the element of memory which binds it to 
the past experience. Recognition is present in the sensory 
presentation of the man to-day as a consciousness of familiar- 
ity which relates the present content to past content. In a 
full and complete recognition there is consciousness of the 
identity in the two experiences, and of the time relationship 
between them. Moreover, the two experiences fall within a 
larger and relatively unchanging content which we shall dis- 
cuss later as the self. This larger content is always involved 
in any single experience incorporating it within a system of 
conscious relationships. Therefore, no single experience 
stands by itself even on the content side of consciousness. 
While the experiences appear to come to the individual in a 
series of sequences, they really interpenetrate each other and 
form an organized continuum. 

Self. — On the subject side of consciousness self, mind, and 
subject are really synonymous terms. The subject self is that 
which persists through all the changing experiences of the 
individual and is therefore the psychical being to which all 
these experiences are presented. Like the mind, it is sup- 
posed to possess powers, capacities, attributes, and disposi- 
tions which account for its outward and observable charac- 
teristics and manifestations. 

But on the content side of consciousness the self is the 
most central, intimate, and persistent core of experience of 
an individual — those experiences which form the complex 
mass of conscious content not always directly attended to, 
but subconsciously present; that content which changes 
slowly but grows and develops as we become more familiar 



1 8 PSYCHOLOGY 

with our own nature and the world about us. It is made up 
of our bodily sensations and sensuous appetites, our private 
feehngs and insistent memories, our real desires and familiar 
thoughts and ideas. These elements are not all present at 
any one moment, but change with the changes of our daily 
life. The organic or bodily sensations and feelings are, how- 
ever, fairly constant, and form a relatively permanent centre 
about which the other self-contents revolve. Sometimes one 
and sometimes another group of experiences combines with 
this constant factor of bodily sensations, and thereby makes 
up the changing aspects of the self. The business man leaves 
his family self behind and puts on another self when he enters 
upon the duties of the day. He passes from one set of habit- 
ual and familiar background experiences to another. He 
shows a different side of his character at the club, on the 
golf-links, or at an evening reception. Yet there is a certain 
identity running through these different groups of self -expe- 
riences which unifies them into a single system of experience. 
Certain of these experiences are more persistent than others, 
and form a background against which all new experiences are 
projected. 

Although, as we have seen, the terms mind and self point 
out the same ultimate reality, as subject of consciousness, 
they are used with different meanings or restrictions. As far 
as the naive metaphysics of psychology go there is practically 
no differentiation between the mind and self. They are both 
the subject which knows and feels and wills, and whatever 
powers and attributes are assumed for the one are usually 
attributed to the other. But on the content side of con- 
sciousness there is a definite limitation. Mind is an organiza- 
tion and unity of conscious content in an individual, while self 
is a central group within the larger organization of the mind. 

The preceding discussion has made plain the fact that 
there are two distinct tendencies in psychology — the philo- 
sophical and empirical. The one leads us into the world of 
speculation and metaphysical reaUty. The other limits us 



INTRODUCTORY IQ 

to the world of observable facts. The one induces us to 
infer and believe in the existence of an enduring ego, mind, or 
soul. The other deals only with the observable content of 
consciousness. The one appeals to our interest in the larger 
problem of the ultimate reality and meaning of our experi- 
ences. The other limits us to an arbitrarily chosen field of 
facts — the facts of consciousness which are abstracted only 
for the purpose of study. While it is our desire to follow 
the empirical tendency, it is not our intention thereby to 
take away, or even to diminish the student's interest in the 
question of the ultimate nature of consciousness. What con- 
sciousness really is, how it came to exist, and what its place 
is in the universe — are questions worthy of our higher reason 
and philosophical insight. No petty round of facts ought to 
ensnare and tame man's desire to know the whole truth. We 
beheve that the world is larger than the facts given us by 
the methods of science. But before we attempt to take the 
broader outlook, our first task is to master the facts just as they 
are given to us — to pick out those that are significant and to 
analyze them into their elements and find out the laws that 
govern their behavior, to evaluate them properly and or- 
ganize them into a system. This is the task that empirical 
psychology sets before itself. 

In a general study of human consciousness such as we are 
going to undertake there are several points of view to be 
kept in mind : 

1. Conscious states must be analyzed and described. In 
doing this we take the structural point of view and ignore 
the functional aspect of consciousness. 

2. We must point out the laws of mental activity accord- 
ing to which conscious states conjoin and form streams of 
thought or feeling. Here consciousness is considered as a 
process and the point of view is functional. 

3. The relation of consciousness to the brain and its nerve 
processes should be determined. When we attempt to do 
this our point of view is physiological. 



20 PSYCHOLOGY 

4. Changes in consciousness that accompany changes in 
the physical world which act as stimuH should be noted. 
This demands the psychophysical point of view. 

5. Finally we must not neglect the relation of conscious- 
ness to behavior. 

We shall not attempt to follow these points of view sep- 
arately. Sometimes one and sometimes another will be 
uppermost in the following discussions. 



CHAPTER II 
THE NERVOUS SYSTEM 

Although the study of the structure and function of the 
nervous system is not properly a part of psychology, it is, 
nevertheless, important for the understanding of the processes 
of conscious hfe to know something of the elementary facts 
in the anatomy, histology, and physiology of the brain. This 
seems necessary since we assume that all consciousness is in 
some way dependent upon the action of the nervous system. 

The brain is connected through nerve-fibres with all parts 
of the body. Some of these fibres (sensory fibres) come from 
the sense end-organs which are played upon by the external 
forces in the environment, and some of them (motor fibres) 
go out to the muscles which bring about adaptive movements 
of the body. Biologically the brain and its nerve-connec- 
tions are merely the means through which external stimula- 
tions are transformed iiito organic behavior. Changes in the 
outer world act upon the sensory nerve-ends and set up 
nerve-impulses which are carried to the brain, where they 
are projected outward into appropriate muscular and glandu- 
lar activities. 

But accompanying these physiological brain and nerve 
processes there is something else which is not discoverable in 
them, and of which physiology can take no account, however 
much its methods may be refined and perfected. This some- 
thing is consciousness. When light-rays strike the retina we 
see. When air-vibrations enter the ear we hear. Besides 
the sensations which arise when external objects stimulate 
the sensory end-organs there are other conscious experiences 
which accompany the neural processes within the brain. 
These experiences are the higher conscious states of percep- 
tion, imagination, memory, judgment, reason, feelings, emo- 



22 PSYCHOLOGY 

tions, etc. Although conscious states depend upon brain 
states, we must not confuse these two forms of existence — 
the mental and the physical. Consciousness is not the brain, 
or any of its neural processes. Even though we were able to 
follow and observe a nerve-activity to its last analysis within 
the brain-cells, we could never discover an element of con- 
sciousness in it. What the exact relation between the mind 
and the brain is we do not know. We can only assert that 
the mind is dependent upon certain brain-activities. 

Consciousness and the Nervous System. — There are sev- 
eral groups of facts which indicate the dependence of con- 
sciousness upon the nervous system: 

1. Consciousness depends upon the action of sense-organs. 
Without the sensitive nerve-endings in eye, ear, nose, mouth, 
skin, and deeper tissues of the body, we could never be aware 
of anything. All the higher forms of consciousness are based 
upon the sensory experiences which are mediated by the 
nerve-endings in the sense-organs. 

2. Certain drugs, like alcohol, ether, hashish, etc., which 
disturb the action of the nervous tissue in the brain, also 
affect consciousness. 

3. Bodily diseases, especially those producing high fever, 
seriously interfere with the conscious processes. 

4. Diseased conditions of the brain — tumors, brain-hem- 
orrhages, lesions, disintegration of the nervous tissue, etc., 
are followed by disturbances or loss of certain forms of con- 
sciousness. Thus a tumor in the occipital region of the brain 
may cause the loss of visual memories. A lesion in the left 
temporal lobe is followed by the loss of the ability to under- 
stand spoken words. 

5. If we compare the different forms of animal life, from 
the lowest to the highest, we find that the most highly devel- 
oped consciousness goes with the most complex and highly 
developed nervous system. 

Development of the Central Nervous System. — ^The cen- 
tral nervous system is made up of the brain and the spinal 



THE NERVOUS SYSTEM 



23 



Medullary plate 



Cuticle-plate 

7— Ectoderm 

Mesoderm 

Entoderm 



Medullary groove 

I f^r~Medullary ridge 




cord. The brain is the mass of nerve- tissue found within the 
cranial case, while the spinal cord is the long tube of nervous 
tissue within the vertebral canal. The brain sends out twelve 
pairs of cranial nerves whose fibres go to the sense-organs 
and muscles of the head, face, and some of the vital organs 
of the body. From the spinal cord 
issue thirty-one pairs of spinal nerves 
whose fibres go to the sensory sur- 
faces and muscles of the body. The 
cranial and spinal nerves are com- 
posed of sensory and motor fibres 
which constitute the afferent and ef- 
ferent pathways between the body and 
the central nervous system. 

We can best understand the struc- 
ture of the nervous system by follow- 
ing its embryological growth. Nerve- 
tissue develops from the ectoderm or 
outer layer of embryonic cells. Very 
early in the growth of the embryo, 
after it has elongated, a longitudinal 

groove, the medullary groove, forms in the medullary plate, 
or beginning nerve- tissue. The edges of this groove come 
together and form the neural tube, which extends along the 
length of the vertebral column and into the cranial cavity. 

The cavity enclosed within the neural tube is the spinal 
canal. This canal, at its upper extremity, later forms the 
irregular ventricles of the brain. The walls of the upper, or 
anterior part of the neural tube thicken enormously and form 
the brain. The walls of the lower part thicken to a less 
degree but more uniformly and form the spinal cord. Within 
the cranial cavity the neural tube forms by ring-like constric- 
tions and dilatations into three primary brain vesicles, known 
as anterior, middle, and posterior vesicles. These three pri- 
mary vesicles give rise to the fore-brain, mid-brain, and hind- 
brain respectively. 



Medullary tube 
Central canal 



Fig. I. — Diagram repre- 
senting the formation 
of the medullary tube 
from the outer germ- 
layer. 

(Taken from Villiger's "Brain 
and Spinal Cord.") 



Thalamus 




Mid-brain 
Cerebellum 




Spinal cord 



Fig. 2. — Ay Diagram showing the brain-vesicles; B, Diagram showing parts 
of embryonic brain v 



Cerebrum 




Cerebellum 



Spinal cord 



IV Ventricle 



Spinal canal 



Fig. 3. — Diagram showing the brain- ventricles 



THE NERVOUS SYSTEM 



25 




I Fore 
iBrain X 



Mid 
Brain 



Hind 
Brain 



Oord 



Fig. 4. — Diagram showing a cross-section of the brain. (Highly diagramatic.) 

Olfactory bulbs and tracts. 

. ^ . I Cerebral hemispheres. 
,- Anterior < „ ^ . ^ ^ 

Corpora striata. 

Lateral ventricles. 



Fore-brain < 



Neural tube 



Mid-brain. 



f Pineal body. 

T-, ^ . Thalami. 

Posterior < ^ .. . 

I Optic tracts. 

[ Third ventricle. 



f Corpora quadrigemina. 

I Crura cerebri. 

[ Aqueduct of Sylvius. 



Hind-brain. 



Pons Varolii. 
Medulla oblongata. 
Cerebellum. 
Fourth ventricle. 



^ Spinal cord. 



20 PSYCHOLOGY 

The Gross Structure of the Brain. — The brain is divided 
by a median fissure into two symmetrical hemispheres. The 
division is not complete, however, for at the bottom of the 
fissure a broad band of fibres, the corpus callosum, unites 
the two halves of the brain. The median fissure extends the 
whole length of the cord and divides it less prominently into 
right and left halves. 

The surface of the brain is furrowed by fissures or sulci, 
which serve to increase the cortical area. The ridges be- 
tween the fissures are called convolutions. Two of the fis- 
sures, deeper than all the others, make convenient landmarks 
on each cerebral hemisphere. They are the lateral fissure 
(fissure of Sylvius) and the central fissure (fissure of Rolando). 

It is sometimes convenient to divide each cerebral hemi- 
sphere into lobes. The frontal lobe occupies the anterior, the 
occipital lobe the posterior, the parietal lobe the upper central, 
and the temporal lobe the lower central part of the cerebral 
hemisphere. The island of Reil forms the fifth lobe of the 
cerebral hemisphere. 

The cerebellum, sometimes called the little brain, lies 
below the cerebrum on the dorsal side of the brain. Below 
and in front of the cerebellum is the medulla oblongata, which 
is an enlargement of the spinal cord at its upper end. Almost 
encircling the medulla oblongata is the pons, a thick band of 
fibres joining the two halves of the cerebellum. 

The cerebral hemispheres are the largest and most con- 
spicuous parts of the fore-brain. The other principal parts, 
the corpora striata, the pineal body, and the thalami, are over- 
laid and concealed from view by the folds of the cerebral 
hemispheres. The hemispheres also enfold the parts of the 
mid-brain, the corpora guadrigemina, and the crura cerebri, 
which lie below the thalami. The pons, medulla, mid-brain, 
and thalami constitute the brain-stem. A medial cross-sec- 
tion of the brain will show all these parts except the corpora 
striata. 

From the ventral and basal side of the brain are given off 



Cer 




Fig. s. — The figure Bn the left shows 

the general relations of the central 

nervous system to the bones of the 

skull and spine. The figure on the 

right displays the general contours of 

the central system as seen from in 

front. The great ganglionated cord 

of the sympathetic system is shown 

attached to one side of the spinal 

nerves; the other side has been cut 

away. Cer., the cerebral hemispheres; 

O, the olfactory centres; P, the "pons 

Varolii; M, th3 medulla oblongata; 

Cb., the cerebellum; Sp.C, the spinal 

cord; /, the olfactory nerve; //, the 

optic nerve; ///, the oculo-motor 

nerve; IV, the trochlear nerve; V, 

the trigeminus nerve; VI. abducens 

nerve; VII, the facial nerve; VIII, 

the auditory nerve; IX. glosso- 
pharyngeal nerve; A', the vagus 

nerve; XI, spinal accessory; XII, 
the hypoglossal nerve; C, the first cervical spinal nerve; Di, the first dorsal, or thoracic, nerve; ii, the first 
lumbar nerve; S\ , the first sacral nerve; Xi, filum terminate; C5', superior cervical ganglion of the sympathetic; 
CS'', middle cervical ganglion of the sympathetic; CS^. and DS^, junction of the inferior cervical and the first 
dorsal, or thoracic, ganglion of the sympathetic; D5", the eleventh dorsal, or thoracic ganglion, of the sym- 
pathetic; L.T' the first lumbar ganglion of the same system; SS\ the first sacral ganglion also of the sym- 
pathetic 

(From Angjll's " Psychology.") 





Frontal lobe 



Precentral gyre 
Central fissure 



Parietal lobe 



Occipital lobe 



Fig. 6. — The upper surface of the cerebral hemispheres. 
(From Ladd and Woodworth, after Sobotta-McMurrich.) 



Central fissure 



Inferior 
frontal gyre 



Supramarginal gyre 
Angular gyre 




Superior 

temporal 

gyre 

Middle 

temporal 

gyre 

Inferior 

temporal 

gyre 

Cerebellum 



Fissure of Sylvius 



Fig. 7. — Lateral surface of the left cerebral hemisphere. 
(From Ladd and Woodworth, after Edinger.) 



Paracentral lobule 



Cingulate fissure Central fissure 



Precuneus 



Limbic lobe 




Parielo -occipital 
firssure 

Cuneus 

Calcarine 

fissure 

Lingual 

gyre 

Cerebellum 



Optic chiasm Mammillary 
body 

Fig. 8.— Mesial surface of the right cerebral hemisphere. 
(From Ladd and Woodworth, after Edinger.) 




Fig. 9 —Under surface of the brain. (From Ladd and Woodworth, after Van Gehuchten.) The 
Roman numerals at the left margin of the figure indicate the twelve cranial nerves; hyp, hy- 
pophysis; cA, optic chiasm; c. warn., mammillary body; ;>c, peduncle of the cerebrum; />/-, pons; 
0, olive; py, pyramids; CI, first spinal nerve. 

29 



30 PSYCHOLOGY 

the twelve pairs of cranial nerves. Some of these nerves carry 
only sensory fibres, some only motor fibres, while others carry 
both sensory and motor fibres (mixed nerves) . 

NAMES AND GENERAL FUNCTION OF THE CRA- 
NIAL NERVES , . 

I. Olfactory: Sensory fibres from olfactory sense-organs. 

II. Optic: Sensory fibres from the visual sense-organs. 

III. Oculo-motor : Motor fibres to several muscles of eyes. 

IV. Trochlear: Motor fibres to superior oblique muscles of eyes. 
V. Trigeminal: Sensory fibres from cutaneous sense-organs of 

face, scalp, mouth, tongue, and teeth. 
Motor fibres to muscles of mastication. 
VI. Ahducens: Motor fibres to external rectus muscles of eyes. 
VII. Facial: Sensory fibres from gustatory end-organs in tongue. 
Motor fibres to muscles of face, scalp, and external ears. 
VIII. Auditory: Sensory fibres from auditory end-organs in cochlea 
(cochlear branch), and from semicircular canals of ear 
(vestibular branch). 
IX. Glossopharyngeal : Sensory fibres from gustatory end-organs. 

Motor fibres to tongue and pharynx. 
X. Pneumo gastric, or vagus: Sensory fibres from respiratory, cir- 
culatory, and digestive organs. 
Motor fibres to pharynx, larynx, oesophagus, stomach, respi- 
ratory organs, and intestines, also inhibitory fibres to 
heart. 
XL Spinal-accessory : Motor fibres to muscles of neck and shoulders. 
XII. Hypoglossal: Motor fibres to muscles of tongue. 

The spinal nerves (31 pairs) are given ofif from the sides of 
the spinal cord. Each nerve is attached to the cord by two 
roots — a posterior root and an anterior root. The posterior 
root is composed chiefly of sensory fibres from cell-bodies in 
the spinal ganglia. The anterior root is composed of motor 
fibres whose cell-bodies lie within the gray matter of the 
cord. The two roots join shortly after leaving the cord and 
form a complete spinal nerve. The spinal nerves are divided 
into cervical (8 pairs), thoracic (12 pairs), lumbar (5 pairs), 
sacral (5 pairs), and coccygeal (i pair). 



THE NERVOUS SYSTEM 



31 



The brain, the cord, the cranial nerves, and the spinal 
nerves make up the cerebrospinal nervous system. 



4_3, 




Fig. 10. — A, ventral, and B, lateral, view of a portion of the cord from the 
cervical region, i, ventral median, and 2, dorsal median, fissures; 5, ventral 
fibres leaving the cord; 6, dorsal fibres entering the cord; 6', spinal ganglion; 
7, spinal nerve after the union of the dorsal and ventral fibres. 
(From Ladd and Woodworth, after Schwalbe.) 



The Autonomic Nervous System. — Besides the cerebro- 
spinal nervous system there is another relatively independent 
nervous system known as the autonomic nervous system. This 
is composed of a double chain of nerve-ganglia and nerve-fibres 
extending on both sides of the vertebral column from the 
base of the skull downward to the end of the column. In 
addition there are nerve-ganglia in the thoracic, abdominal, 
and pelvic cavities ; also isolated ganglia located in the heart, 
in the walls of the arteries, and in the eye-cavities. While the 
autonomic system is connected with the cerebro-spinal ner- 



32 



PSYCHOLOGY 




^'Dendrites 



^Collaterals 



Axon 



Fig. II. — Nerve-cell from the 
cerebral cortex. 



vous system, it is a relatively 
independent and self-directing 
system. It is due to its action 
that the vital and automatic 
processes of respiration, circula- 
tion, digestion, and the glandular 
processes are carried on without 
burdening the central nervous 
system. 

Nerve-Cells. — The nervous 
system is composed of millions 
of nerve-cells too small to be 
seen except by the aid of a power- 
ful microscope. The nerve-cell 
is composed of a protoplasmic 
cell-body and its prolongations or 
fibres. These prolongations are 
of two kinds: axons and den- 
drites. The whole nerve-cell (cell- 
body, axon, and dendrites) constitutes a nervous unit known 

as the neurone. Each cell-body gives off many dendrites, 

but in most cases only a sin- 
gle axon. The axon is smooth 

and regular in contour and 

preserves the same diameter 

throughout its course. It 

ends in a brush or terminal 

arborization. In some cases 

it gives off, along its course, 

branches or collaterals, and 

these end also in terminal 

arborizations. Axons vary 

greatly in length. While 

those which terminate within 

the brain are short, those 

which lead to outlying parts 




Dendrites 



Fig. 12. — Multipolar nerve-cell from 
the cerebral cortex. In a cell of 
this type the axon is short and has 
many branches. 



PR-^., 



kl.PD 




Fig, 13. — A section through the brain cortex. Greatly magnified. 
(From Thomdike's "Elements of Psychology," after KoUiker.) 



34 



PSYCHOLOGY 



may be half the length of the body. The true nerve sub- 
stance of the axon (the axis cylinder) is protected by a 
medullary sheath which disappears near the cell-body and at 




Fig. 14. — Nerve-cell showing fibrils. 
(From Ladd and Wood worth, after 
Bethe.) a, b, c, d, the stumps of 
several dendrites; Ax, stump of 
the axon. 



Fig. 15. — Short pieces of two nerve- 
fibres. (From Ladd and Woodworth, 
after Schafer.) The axis cylinder 
appears gray, the myelin sheath is 
stained black; the primitive sheath ap- 
pears white. R, node of Ranvier; c, 
the nucleus of one of the sheath-cells. 



the terminals of the axon. Outside the medullary sheath is 
usually found a thin covering known as the neurilemma. 
The dendrites are rough and branch more gradually from 




J^SS* 



Fig. 1 6. — Motor-cell from the ventral horn of the cord, with scheme of the 
course of its axon. (From Ladd and Woodworth, after Barker.) n, the 
nucleus, with m^ nucleolus; d, dendrites, only the stumps of which are 
shown; a.h., hillock from which the axon arises; at m, the axon becomes 
invested with the myelin sheath; n.R., a node with branching of the axon; 
m}, a muscle in which the axon terminates in tel., the motor end-plate. 



30 PSYCHOLOGY 

each other, giving off antler-Hke processes. The size of the 
dendritic processes becomes rapidly smaller as they leave 
the cell-body. The nerve-cells are supported and held in 
place by neuroglia-cells whose numerous processes form a 
frame work in which the true nerve- cells rest. 



Dendrites 




Fig. 17. — Diagram showing the probable way in which neurones are connected. 

The function of the cell-body seems to be that of rein- 
forcing and inhibiting the nerve-impulses which pass through 
them. The dendrites carry the impulses to the cell-body and 
the axon transmits the impulse away from the cell-body — to 
the dendrites of other neurones or to the glands and muscles 
of the body. There is one exception to this rule. The fibres 
which carry sensory impulses from the different sense-organs 
to the cell-bodies in the spinal ganglia resemble axons in 
structure. 

How the nervous impulse is transmitted from one neurone 
to another is not definitely known. Many investigators be- 
lieve that each neurone is a distinct individual unit, and that 
where neurones form a functional chain, the axonic terminals 
of one neurone merely approach the dendrites or cell-body 
of the next neurone. These points of contact or contiguity 



THE NERVOUS SYSTEM 



37 



between neurones over which the nerve-impulse is passed 
from one to the other are called synapses. Since the axons 
and dendrites have many branches, the terminations of one 



^^rum 




Motor neurones in 
Ventral horns 

Fig. i8. — Diagram of some of the connections between sense-organs and 
muscles through the cord and brain. 

The student should understand that this diagram is far too simple to represent all the facts of 
nerve-connections. 



axon may connect with the dendrites of a number of other 
neurones. Thus an Impulse may spread to large areas of 
the brain and under different conditions take different path- 



38 PSYCHOLOGY 

ways through the cord and brain. A single fibre from the 
spinal ganglion makes connections with fifty or sixty differ- 
ent neurones in the gray matter of the cord. 

Nature of the Nervous Impulse. — Just what the nature 
of the nervous impulse is we are not able to say. The most 
popular theory regards it as a form of chemical activity 
analogous to the action in a train of gunpowder, which when 
lighted at one end transmits the combustion throughout its 
entire course. It has been suggested, also, that the nervous 
impulse is electrical in nature. But the rate of nerve trans- 
mission (not more than 300 feet per second) is much too slow 
for that of any known electrical action. 

Kinds of Neurones. — Neurones may be classified accord- 
ing to their function into (i) sensory or afferent neurones, 
(2) motor or ejferent neurones, and (3) associational or central 
neurones. The sensory neurones receive stimulation from the 
outside world and conduct sense-impulses to the sensory 
centres of the brain. The motor neurones project impulses 
outward from the brain to the muscles and glands. The cen- 
■ tral neurones form chains for connecting the different parts 
of the brain, as for instance from the sensory to the motor 
areas. When neurones pass from one-half of the brain or 
cord to the other half they are spoken of as commissural 
neurones. 

The cell-bodies of the central and motor neurones lie 
within the brain and spinal cord, while the cell-bodies of the 
sensory neurones are found near the sense-organs or in the 
spinal ganglia outside the brain and cord. When a large 
number of cell-bodies are grouped closely together the group 
is spoken of as a ganglion. 

The separate nerve-fibres are (except at their terminals) 
bound together in bundles or nerves. They are referred to 
as medullated and non-medullated nerves, according as the 
fibres which compose them are medullated or non-medullated. 

White and Gray Matter. — The white matter of the brain, 
cord, and nerves is made up of medullated nerve-fibres. It is 



THE NERVOUS SYSTEM 



39 




the medullary sheath which gives the whitish appearance. 
The gray matter is the true nerve substance and is found in 
the cell-bodies and in the fibres. In the meduUated fibres 
the true nerve substance is hidden from view. The gray sub- 
stance comprises the cortex or outer layer of the brain, cer- 
tain ganglia within the brain, 
and the central core of the 
spinal cord. The entire outer 
surface of the brain is cov- 
ered with a layer of gray 
matter (cell-bodies and un- 
medullated fibres) properly 
protected from the bony tis- 
sue of the skull by three 
membranes — the dura mater, 
the arachnoid, and the pia 
mater. The corpora striata, 
thalami, corpora quadrigem- 
ina are also composed of 
masses of gray matter. In 
the medulla and other parts 
are found smaller masses of 
gray matter called nuclei. 

The white matter of the brain is made up of the bands 
and bundles of medullated nerve-fibres connecting the cortex 
and the lower brain ganglia. The white matter in the cord 
(the outer layers) is made up of medullated fibres passing 
to and from the brain. 

The true nerve substance possesses two chief character- 
istics — irritability and conductivity. By irritability is meant 
the capacity to respond to stimulation by some kind of nerve 
process, and by conductivity the capacity to pass the nerve 
impulse from one point to another. The impulse is carried 
from dendrites to axon through the cell-body. The cell- 
body possesses the power to modify the impulses by rein- 
forcing or inhibiting them. The direction which an impulse 



Fig. 19. — Frontal section through the 

cerebral hemispheres. 

(From Ladd and Woodworth, after Gegenbaur.) 

The shaded portions represent the cortex and 
ganglia (gray matter). The light portions rep- 
resent the mass of medullated fibres within 
the brain (white matter). 



40 



PSYCHOLOGY 




takes through the brain is determined by the condition of 
the synapses at the moment, and this is determined by the 
modifications of the brain tissue handed down through hered- 
ity and by those made by the past experiences of the organism. 
The Fibre Connections of the Brain. — The medullated 

fibres which consti- 
tute the great nerve 
tracts of the brain 
and cord may be con- 
sidered under three 
groups: (i) Projec- 
tion fibres, (2) associ- 
ation fibres, (3) com- 
missural fibres. 

(i) The projection 
fibres join the cortex 
with the rest of the 
brain and with the 
spinal cord. These 
fibres bring in im- 
pulses from the sense- 
organs and send out 
impulses to the mus- 
cles. Those that 
bring in the sensory 
impulses are called 
the ascending fibres, while those that send out the motor 
impulses are called the descending fibres. 

The descending fibres are axons from the motor neurones 
in the cerebral cortex. Of these fibres those which go to the 
nuclei of the cerebral nerves are known as geniculate fibres. 
As they pass downward into the lower brain they cross over 
to the opposite side, and there in the nuclei of the motor 
cerebral nerves communicate with the neurones which go to 
the muscles of the head and neck. The other descending 
fibres from the cerebral cortex communicate with the motor 



Fig. 20. — Diagrammatic cross-section through 
the cord showing gray and white matter. 
WW, white matter or medullated fibres; 
GG, gray matter; A, afferent sensory fibres 
passing through S. G., the spinal ganglion, 
into the posterior horn of the gray matter; 
E, efferent motor fibres, most of which lead 
to muscles like M, many of which connect 
with the sympathetic ganglia, like Sy; C, 
central cell, probably traversed as a rule by 
impulses passing from A to E; DP, dorsal, 
or posterior, surface of cord; VA, ventral, 
or anterior, surface. 

(From Angell's "Psychology.") 



THE NERVOUS SYSTEM 



41 




Motor fibres from 

anterior horn 

of cord 



Fig. 21. — The motor tract. 



neurones in the anterior horns of the spinal cord. They are 
known as the pyramidal fibres. From the cerebral cortex 
they pass down through the internal capsule to the pyramids 



42 



PSYCHOLOGY 




Sensory fibres 
of posterior 
nerve roots 



Fig. 22. — ^The sensory tract. 



of the medulla. Here the larger part of the pyramidal 
fibres cross to the opposite side and descend in the lateral 
column of the cord as the crossed pyramidal tract. In each 



THE NERVOUS SYSTEM 43 

segment of the cord pyramidal fibres enter the gray matter 
of the cord and communicate with the motor neurones in the 
anterior horn, where originate the motor nerves which go to 
the muscles of the body. Some of the pyramidal fibres, 
forming the direct pyramidal tract, pass downward in the 
anterior column without crossing. These fibres, however, 
finally cross to the opposite side of the cord at lower levels, 
and in each case they communicate, as do the crossed pyram- 
idal fibres, with the motor neurones in the anterior horn. 
Thus it is seen that each cerebral hemisphere controls the 
muscles on the opposite side of the body. Beside the fibres 
already described, other descending fibres run from the cere- 
brum to the cerebellum, which in turn sends fibres to the 
lateral and anterior columns of the cord. 

The ascending projection fibres form the sensory tracts 
leading from the ganglia of the cerebral and spinal nerves. 
Nearly all the sensory fibres of the cerebral nerves go to the 
sensory nuclei in the medulla and pons. From these nuclei 
axons cross to the opposite side and communicate with the 
thalamus. From here other fibres send on the sensory im- 
pulses to the various parts of the cortex. In a similar man- 
ner the sensory fibres from the spinal nerves go from the 
spinal ganglia through the cord to nuclei in the medulla. 
From there new axons cross to the opposite side and pass 
through the mesial fillet to the thalamus and mid-brain, and 
thence to the cerebral cortex.^ Thus impulses from the 
sense-organs from one side of the body are sent through a 
chain of neurones to the cortex of the opposite hemisphere. 
Beside the nerves which connect the sense-organs with the 
cerebrum there are other projection fibres which pass from 
the cord and medulla to the cerebellum, and from the cere- 
bellum to the cerebral hemisphere. 

^ There are exceptions to this general rule. Many fibres from the sense- 
organs in the skin cross in the cord and pass upward in the opposite side of 
the cord. Some of the fibres from the sense-organs in the muscles pass upward 
in the same gide of the cord and go to the cerebellum without crossing. 



44 



PSYCHOLOGY 



The fibres of the optic nerves follow a somewhat different 
course from that of the other cerebral nerves. The fibres 
from the inner or nasal half of each eye cross in the optic 



Occipital lobe 



Optic radiation 
Superior colliculus 



Lateral or external 
geniculate. 

Optic thalamus 




Fig. 23. 



Retina 



-Scheme showing the distribution of the optic fibres. 
(From Howell's "Text-Book of Physiology.") 



chiasma and go to the opposite side of the brain, while the 
fibres in the outer or temporal half of each eye go to the 
same side of the brain. These fibres from the retinae end in 
the region of the thalami and upper quadrigeminal bodies. 
This region constitutes the lower visual centres. From here 
new fibres continue to the occipital lobes of the cortex and 
enid there in the higher visual centres. 



.Cerebrum 



Snperior 
Go7-p. Quad. 




Superior/ 
Olive 

^Cochlea 

. ">" 

Semicircular 
Canals 

Fig. 24. — Scheme showing the distribution of the cochlear fibres. 



Nuclei of 
Motor Cerebral 
Nerves 




Fibres to 
Cord 



Cochlea 



. . y 

Semicircular 
Canalu 

Fig. 25. — Scheme showing the distribution of the vestibular fibres. 



46 



PSYCHOLOGY 



The auditory nerve contains fibres from two different 
parts of the ear — the cochlea and the semicircular canals. 
The cochlear fibres go to the temporal lobes of the cerebrum, 
while the fibres from the semicircular canals go to the cere- 
bellum. 




Fig. 26. — Cut showing the association fibres joining the different cortical 

centres with one another. 

(From Ladd and Woodworth, after Starr.) 



(2) The association fibres form the nerve pathways which 
connect the different parts of the same cerebral hemisphere^ 
with each other. The sensory impulses which are projected 
from the sense-organs to the various sensory centres within 
the brain are reflected, or projected, back to the muscles from 
the motor centres, and find expression in movements. Now 
the connection between the different sensory centres and 
between the sensory centres and the motor centres are made 
by the association fibres. By means of short and long fibres 
both adjacent and remote areas of the cortex are connected 
with each other. The higher processes of consciousness — 
perception, imagination, memory, thought, etc. — demand the 

* Or the cerebellar hemisphere. 



THE NERVOUS SYSTEM 



47 




co-operation of the various sensory areas and depend, there- 
fore, upon the associative connections between them. 

Complex forms of conscious behavior also depend upon 
the co-operation of different parts of the cortical areas. 

(3) The commissural 
fibres are found in all parts 
of the central nervous sys- 
tem. They are the fibres 
which connect one hemi- 
sphere of the brain and 
cord with the other. In 
the cerebrum the most 
prominent commissural 
pathways are formed by 
the corpus callosum and 
the anterior commissure. 
The fibres of the corpus 
callosum join the cortex of 
one side with that of the 
other. The fibres of the 
anterior commissure con- 
nect the temporal lobes of opposite sides. 

Localization of Function. — With regard to function the 
subdivisions of the brain may be classed under two headings, 
the higher centres and the lower centres. The higher centres 
are located in the cortex of the cerebral hemispheres. These 
centres constitute the neural basis for the intellectual proc- 
esses. The lower centres are found between the cerebral 
cortex and the cord and include the thalami, the corpora 
quadrigemina, the medulla oblongata, the pons, the cranial 
ganglia, and the cerebellum. The lower centres control, 
more or less independently of the higher conscious processes, 
the vital or vegetative processes of the body. 

The area of general sensations — pressure, pain, and tem- 
perature sensations — occupies the convolution just pos- 
terior to the fissure of Rolando. The kinassthetic sensa- 



FiG. 27. — A transverse section through 
the two hemispheres showing com- 
missural fibres connecting the hemi- 
spheres. 
(From Judd's "Psychology," after Edinger.) 



48 PSYCHOLOGY 

tions, or sensations of movement, also have their seat in 
this region. 

The auditory area is located in the superior convolution of 
the temporal lobe. 

The visual area is found in the cuneus and gyrus lingualis. 

The olfactory area is situated in the forward part of the 
hippocampal convolution. 

The gustatory area has not been definitely located, but is 
supposed to be situated in the hippocampal convolution just 
behind the olfactory area. 

The areas which immediately surround, or lie adjacent to, 
the sensory areas proper, are supposed to be sensory psychic 
areas, or the areas involved in the understanding or com- 
prehension of the sensations themselves. For instance, 
merely to hear a sound is one phase of the experience. To 
understand the sound as the sound of a bell, or of a passing 
street-car, is another phase of the experience. The psychic 
areas are responsible for this latter function. Injury to these 
areas may leave the individual able to hear, or see, or taste, 
etc., without being able to understand the nature of the 
sensations. 

The motor area lies just in front of the fissure of Rolando 
in the precentral convolution and extends into the superior, 
middle, and inferior convolutions of the frontal lobe, and 
into the mesial surface of the hemisphere. The motor area 
may be divided into upper, middle, and lower regions. The 
muscles of the face, tongue, and larynx are controlled by the 
lower region; the muscles of the shoulders, arms, hands, and 
fingers are controlled by the middle region; the muscles of 
the trunk, legs, and feet are controlled by the upper region. 
In most cases the motor centres of one hemisphere control 
the muscles of the opposite side of the body. This is not, 
however, universally true. Certain muscles of the face, the 
muscles of mastication, and those of the pharynx and larynx 
receive motor fibres from both hemispheres. The fact that 
destruction of the motor centres in one hemisphere is not 



Fis sure of Rolando 




Jictlulla 
Cord 



Fig. 28. — Areas of localization on the lateral surface of the hemisphere. 
Motor area in red; bodily sense area in blue; auditory area in green; 
visual area in yellow. 



Hippocampnl 
Convolution 




rebeliwm 



Fig. 29.^Areas of localization on the mesial surface of the hemisphere. 
Motor area in red; bodily sense area in blue; visual area in yellow; olfac- 
tory and gustatory areas in purple. 



THE NERVOUS SYSTEM 



49 



followed by complete paralysis of the muscles on the opposite 
side, indicates that these muscles are partially controlled by 
the motor centres of the other hemisphere. 

The association areas occupy portions of the cerebral hemi- 
spheres not taken up by the sensory and motor areas. Three 




Fig. 30. — Diagram showing the chief regions of the motor and sensory centres 



large areas may be designated as association areas: the an- 
terior associational area occupies the fore part of the frontal 
lobe; the middle associational area occupies the Island of Reil; 
the posterior associational area occupies a large part of the 
occipital and temporal lobes and practically all of the parietal 
lobe. These areas are supposed to be the centres for the 
higher conscious processes — the intellectual centres, so to 
speak. It is here that the various sensory experiences are 
co-ordinated and elaborated into processes of knowledge and 
thought. These centres are often referred to as the Flechsig 
areas from the fact that Flechsig first pointed out that the 
myelination or development of the medullary sheath of the 
nerve-fibres to these areas takes place only after the myelin a- 



50 PSYCHOLOGY 

tion of the nerve tracts to and from the sensory and motor 
centres has taken place. At birth, according to Flechsig, all 
the sensory fibres of the lower parts of the brain are devel- 
oped, but only two tracts — the olfactory and the gustatory — 
are developed within the cerebrum. Gradually, however, the 
tactual, visual, and auditory tracts become myelinated and 
ready to function. The tracts from the various sensory cen- 
tres to the association areas are the last to develop. Upon 
this fact, together with the supposed fact that the cellular 
structure within the association areas is uniform and differ- 
ent from that in the sensory and motor areas, he based his 
theory that the association centres are the higher intellectual 
centres. Later investigators have demonstrated that not 
only do the several sensory and motor centres show a differ- 
ent cellular structure, but the various parts of the association 
centres also show differentiation in this respect. If each 
specific form of cell-structure of the cortical areas corresponds 
to a particular mental function, the association areas will 
some day be mapped out to indicate the localization of the 
different intellectual functions. At present, however, we 
know very little about the function of these large association 
areas. There is sufficient evidence to establish the fact that 
certain parts of these areas lying adjacent to the sensory 
centres serve as memory areas for these centres. For in- 
stance, clinical cases have been reported in which loss of 
ability to recognize objects seen, or held in the hand, or heard, 
follows a lesion in the brain areas in the immediate vicinity 
of the visual, tactual, or auditory sense areas respectively. 
In such cases the patient can see and feel and hear the ob- 
jects, but memory for the sensory experiences is lost. On 
the other hand, while destruction of the sense centres alone is 
followed by blindness, deafness, etc., memory for the sensa- 
tions received before the injury is still intact. 

The motor speech centre lies in the inferior frontal convo- 
lution in the left cerebral cortex. Injury to this centre 
{Br oca's Centre) is followed by the loss of the abihty to 



THE NERVOUS SYSTEM 5 1 

speak properly. This condition is known as motor aphasia. 
Broca's convolution is evidently not the centre for the mus- 
cles of speech; for in cases of motor aphasia the patient is 
still able to pronounce words. The words do not, however, 
form sentences or express meaning, but are hopelessly mixed. 

The sensory speech centre also is found on the left side in 
the posterior part of the superior temporal convolution and 
in the adjoining part of the superior marginal convolution 
(Wernicke's Centre). Injury to this centre is followed by the 
loss of the ability to understand spoken words. The patient 
is still able to hear words, but he fails to comprehend them. 
This condition is known as word-deafness or sensory aphasia. 

The visual centre for written language lies just posterior to 
Wernicke's Centre in the angular convolution. Injury to 
this centre is followed by the loss of the ability to recognize 
or understand printed or written characters. The patient is 
able to see the characters, but they mean nothing to hiin. 
This condition is known as word-blindness, or alexia. 

The speech centres seem, therefore, to be psychic centres 
within which images of the movements of articulation, of the 
sound of words, and of the visual forms of written characters 
are aroused. When such mental representation is made im- 
possible by brain lesions, aphasia, or the inability to use or 
understand words, results. 

It has been claimed by some authorities that the language 
centres in left-handed persons are located on the right side 
of the brain, but this claim has been denied by other investi- 
gators. 

The two halves of the brain are not identical in function. 
Not only is speech a one-sided function, but many consecu- 
tive and skilled movements of the hands and fingers are con- 
trolled by one side of the cerebral cortex, usually the left 
hemisphere. In many cases of lesions of the left hemisphere, 
followed by paralysis of the right hand, there is also a serious . 
impairment of the ability of the left hand to execute move- 
ments. Cases have been reported in which lesions in the 



52 PSYCHOLOGY 

corpus callosum, the band of fibres which connects the two 
hemispheres, are followed by a lessening of the abihty to 
use the left hand, a result due, without doubt, to the fact 
that the conscious factors involved are conditioned by the 
left cortex. It would seem, therefore, that the images neces- 
sary for the conscious control and execution of certain ac- 
quired movements depend very largely upon the activity of 
the left cerebral cortex. 

The higher complex intellectual processes are probably 
not located in any single cortical area, but depend upon the 
co-ordinated activity of many, if not all, of the cerebral areas. 



CHAPTER III 

ATTENTION 

If we examine our consciousness at any moment we find 
that a part of its content stands out in bold relief from the 
rest — that we are mentally occupied with some one presenta- 
tion of the senses, or engaged in the elaboration of some 
thought or idea, at the expense of other possible presentations 
or ideas. In other words, we find that some part of the con- 
tent is clearer and more definitely in consciousness than the 
rest of it. If our eyes rest upon a landscape, some one object 
momentarily occupies the centre of our awareness. If we 
listen to the sounds of the street, some one sound is clear and 
distinct, or at least clearer and more distinctly apprehended 
than the other sounds of which we are conscious. If we are 
absorbed in meditation, some one idea is uppermost in our 
thinking. We further observe that there is a constant shift- 
ing of the elements of the total content. Now one and now 
another part of the content becomes clear and definite, and 
then fades to give place to its successor. There is a constant 
change from clearness to obscureness and from obscureness 
to clearness. We also find that, at any one time, although 
there are a number of different objects appealing to the 
senses, or different ideas that might be entertained in the 
mind, yet it is always one of them, or a single group of them, 
that occupies the centre of the stage. Another fact we notice 
is that the changes in the content take place in a definite 
order, either in accord with some inner plan of action or 
thinking, or in conformity to the order of presentation of 
outer objects. We shall see in a later chapter that the rise 
and fall of ideas in the clearest part of consciousness takes 
place according to a general law — the law of association. 

53 



54 PSYCHOLOGY 

For instance, if at this moment I am thinking of Harvard 
University, the next clear thought that comes into my mind 
is that of Professor James. This is because of the past asso- 
ciation of these two thoughts in my experience. 

We also notice that these changes in the nature of con- 
sciousness are accompanied by impulses to movements in the 
various parts of the organism, especially in the muscles of 
accommodation of the sense-organs. The eyes are adjusted 
in seeing. The head is turned in hearing. Movements of 
inhalation are made in smelling. These movements serve to 
make the stimulus in each case more effective. Besides the 
movements of sense-accommodation, other movements of the 
body can be detected. Facial expressions and bodily atti- 
tudes conform to the changes of thought. The wrinkled brow 
and the constrained attitude are usually present in deep 
thought. The smile and the frown each correspond to defi- 
nite qualities of consciousness. Changes in heart action and 
respiration parallel the changes in mental activity. So we 
can say that wherever consciousness changes its direction, 
there we may find impulses to movement. 

As a result of movements of accommodation in the sense- 
organs and expressions in other parts of the body during the 
activity of consciousness, there arises a complex of sensations 
which become a part of the content of experience. This com- 
plex is made up of sensations of strain and effort in the various 
muscles. When we listen for a certain sound we distinctly 
feel the tension of the muscles of the neck and the faint sen- 
sations in the muscles of the middle ear. When we look for 
a certain object in a scene before us we feel quite as dis- 
tinctly the movements of the eyes. When we try to remem- 
ber or solve a difficult problem we feel the sensations of 
strain in the muscles of the forehead. All these sensations 
are designated by the term kinassthetic sensations — sensations 
of movement. 

Lastly we notice that the changes in consciousness are 
often co-ordinate with feeling. The ideas and thoughts that 



ATTENTION 55 

come clearly into our minds, and find lodgment there, are 
frequently those that appeal to us — those that refer to things 
we like or those that are useful in avoiding the things we dis- 
like. We seek the pleasant and avoid the unpleasant. Con- 
sequently the ideas and sensations that become clear and 
definite are those that possess affective qualities. 

Now, in our examination of consciousness we have noted 
the following characteristics: 

1. Structure into clear and unclear parts. 

2. Change of content. 

3. Selection of certain parts of the total content. 

4. Sensations of adjustment^kinassthetic sensations. 

5. Affective quality. 

These are the characteristics of consciousness which make 
up attention. At one time or another in the history of psy- 
chology each of these characteristics has been picked out and 
put forward as the fundamental character of attention. 
This accounts for the various definitions and points of view 
which we meet in the literature of the subject. 

If now, in addition to the content which we discover in 
the attention-consciousness, we assume or infer a subject of 
consciousness, or a permanent mind back of the content, we 
might be tempted, like some of the older psychologists, to 
define attention as the power of the mind to concentrate, 
change, and prolong conscious states. But by so doing we 
run into a cul-de-sac^ for after defining attention as "the 
power of the mind," et cetera, we can go no further with the 
definition, because we know nothing about this mind, or ego, 
or self which exerts its power in this way. We cannot find 
out how it concentrates, changes, or prolongs conscious states. 
We gain nothing by this definition of attention beyond a con- 
venient way of holding the facts together in our thinking. 
The danger of such a conception of attention lies in taking it 
as an explanation of the facts. However, it is a convenient 
way of speaking into which we often fall, even in empirical 
psychology. We speak of "the power of the mind to con- 



56 PSYCHOLOGY 

centrate," "the activity of the mind in attending," or use 
other expressions which seem to infer that attention is some 
power back of the conscious states. If we understood what 
was said in the introductory chapter, it will be unnecessary 
when we use such expressions to stop and explain that we are 
not referring to a metaphysical entity by the words "mind" 
or "self," or that we look upon attention as something other 
than that found in the content of consciousness. It is true 
that in our popular thinking the clearness, the changes, the 
selection, and the motor impulses of conscious states are 
looked upon as due to the activity of some agent which we 
beheve exists behind the contents of consciousness. But 
popular thought is saturated with uncritical metaphysics. 
Our business is first to consider the facts. All that introspec- 
tion reveals to our observation in attention are the five char- 
acteristics which we have just enumerated. Of these charac- 
teristics of attention the most important one — the mark by 
which we define attention — is clearness. Clear or vivid con- 
sciousness is a universal characteristic of all attention, and 
unclear consciousness a characteristic of non-attentive con- 
sciousness. Several ways of describing the structure of con- 
sciousness in which attention appears have become current 
in psychology. The difference between attentive conscious- 
ness and non-attentive consciousness may be described as 
one of degree or level.^ Attention is a high-level, while non- 
attentive consciousness is a low-level consciousness. The dif- 
ference between the levels is, of course, that of degree in the 
clearness of consciousness. Whether there are only two de- 
grees of clearness, or several degrees or levels, cannot be 
determined at the present time, although the experimental 
evidence favors the hypothesis of several degrees, which shade 
ofif from the highest degree of close or rapt attention to the 
lowest degree of diffused consciousness. 

Another way of picturing the structure of consciousness 
is illustrated in Figure 3 1 . Attention would then be the cen- 
^Titchener; "Textbook of Psychology," p. 276, 



ATTENTION 



57 




tral circle, while the degrees of diffused or vague conscious- 
ness would be represented by a series of widening circles. 
The central circle is spoken of as the focus of consciousness, 
and the outer circles as the fringe, or margin, of consciousness. 

Sometimes it is convenient to 
speak of attention as the fore- 
ground of consciousness, and non- 
attentive consciousness as the 
background. The foreground is 
clear and distinct, while the back- 
ground is diffused or unclear. 

All these pairs of terms — clear 
and unclear, high-level and low- 
level, focus and margin, foreground 
and background — describe the 
same fact, the difference in struc- 
ture in the contents of conscious- 
ness at any one moment. The 
first term in each pair refers to the 
wide-awake and effective part of 
the conscious field, and suggests 
that attention is clear and central consciousness. 

The fact that attention is constantly changing its direc- 
tion, now resting upon this object, and now upon that, is 
another characteristic that we have noted. No conscious 
state remains clear or focal for any length of time. This has 
given ground for the definition of attention as the most active 
part of consciousness, and has introduced the idea of atten- 
tion as a process, or an activity, a functional characteristic as 
distinguished from the structural one we have just been dis- 
cussing. And then the further observable fact that atten- 
tion gives itself to one of many objects presented to the 
senses, or to one of many possible lines of thought, adds 
another characteristic to the conception of attention and 
gives rise to the definition of attention as selective conscious- 
ness. If we emphasize the fact that attention involves cer- 



Fig. 31. — Graphic representa- 
tion of the field of conscious- 
ness: I, attention, or the 
focus of consciousness; 2 
and 3, fringes of diffused 
consciousness; 4, subcon- 
sciousness. 



58 PSYCHOLOGY 

tain adjustment activities which turn the sense-organs toward 
the object to be attended to, or that certain movements of 
the body are made anticipatory to ideas we entertain in atten- 
tive thinking, we have still another characteristic. It is in 
this case rudimentary will, or conation. And still again, if we 
pick out the sensations of strain and effort in these move- 
ments of accommodation we have another characteristic 
which we may look upon as the chief mark of attention. We 
may then define attention as a complex of kinaesthetic sensa- 
tions which we sense as efort. If, in turn, we emphasized the 
fact that consciousness follows the lead of our feelings, we 
could then define attention in terms of the affections or feel- 
ings which control the direction of conscious activity. 

Bringing all these characteristics together, we have atten- 
tion defined variously as clear, active, selective, volitional or 
conative, effortful, and affective consciousness. But this is a 
list of the fundamental characteristics of consciousness itself. 
What we have been describing is a whole state of conscious- 
ness. Attention is just consciousness at its best — conscious- 
ness doing its work with its greatest efficiency and despatch. 
Attention is not a separate or independent function, but "the 
mind at work or beginning to work upon its object."^ It is a 
common and constant function of all efficient consciousness. 
All processes and conditions of fully developed consciousness 
take place in attention. Sensation, perception, imagination, 
memory, judgment, conception, reason, emotion, and will 
occur most completely at the crest of the wave of attentive 
consciousness. Attention, then, is any state of consciousness 
that is fully and completely conscious, fully and effectively 
active. 

Forms of Attention. — The existence of many phases or 
characteristics of attention makes possible a variety of classi- 
fications of the kinds of attention. Since all of these char- 
acteristics are not equally present in all cases of attention, 
their presence or absence forms a basis of classification. 

^ Attention— Baldwin's "Dictionary of Philosophy and Psychology.'' 



ATTENTION 59 

Attention is sometimes set up and controlled by the inten- 
sity and character of outside stimuli, and sometimes by the 
activity of consciousness itself, i. e., by conscious plans or 
purposes within the mind. Again some cases of attentive 
consciousness show a marked degree of effort and strain, 
while other cases contain very little or none at all. Some- 
times attention is occupied by sensory stimulation and ma- 
terial objects, and sometimes it is absorbed in the intellectual 
processes of memory, judgment, and reason. The classifica- 
tion of the forms of attention varies accordingly as we em- 
phasize one or the other of these facts. 

One of the most popular classifications is that which di- 
vides attention into — 

1. Non- voluntary attention. 

2. Voluntary attention. 

3. Involuntary attention. 

Non-voluntary attention is the attention given to any 
mental content without being directed or controlled by con- 
scious purpose or attended by efifort of any kind. In popular 
language we say that it is attention without the will. Non- 
voluntary attention may occur in young children before 
conscious purpose is developed when the direction of their 
thoughts is determined by influences outside of themselves, 
and in adults when conscious purposes are in abeyance. In 
the case of the child, sounds, colors, lights, and moving ob- 
jects will easily attract and hold his attention. As he grows 
older, familiar and interesting topics of thought will capture 
his attention without effort or purpose on his part. In the 
case of the adult, non-voluntary attention is found in flights 
of fancy, day-dreaming, and when we have become thoroughly 
absorbed in some interesting subject, or topic of thought, 
where effort or expHcit purpose is not necessary to hold the 
attention. Non-voluntary attention has sometimes been 
called spontaneous attention. It is spontaneous only in the 
sense that it springs up without self-constraint, and repre- 
sents the native and acquired tendencies that are firmly im- 



6o PSYCHOLOGY 

planted within us. First our organic needs — food and shelter 
stimuli, and situations which call for actions of self-defense 
- — attract and hold the attention. Later, the things that are 
in conformity with our acquired characteristics and touch 
the chords of our maturer nature appeal successfully to the 
attention. 

Voluntary attention is the attention we give as a result of 
some conscious purpose or plan which we wish to carry out, 
and is always attended by feelings of effort and strain. It is 
attention with will. Plainly, voluntary attention is possible 
only where mental development has reached a certain degree 
of perfection, for it involves the presence in the mind of pur- 
poses and desires which are the result of past experiences, 
and which are represented in consciousness as a future mode 
of activity. Voluntary attention is evidently an outcome of 
non- voluntary attention. Conscious purpose and choice can 
arise in the mind only as an outcome of a conflict in non- 
voluntary attention. When two or more rival stimuH bid 
for the central position in consciousness, then voluntary 
attention becomes possible as self-initiated and self-directed 
consciousness. What enters the mind then is determined by 
premeditated choice. Voluntary attention may be trans- 
formed into non-voluntary or spontaneous attention. Where 
at first we attend with conscious effort and with difficulty, 
we in time come to attend spontaneously, and therefore with- 
out effort. Voluntary attention, then, has both its beginning 
and its end in spontaneous attention. 

Involuntary attention is the attention we give to any ob- 
ject or topic of thought in spite of, or in direct opposition to 
our desire to attend to something else. It is attention against 
the will. The thing we attended to forces itself upon us even 
though we strive to keep it out of our consciousness. In- 
tense stimulation of any kind, loud or sudden sounds, bright 
lights, abrupt changes, moving objects, bodily pain, insistent 
or fixed ideas, consuming sorrows and alluring pleasures, all 
force themselves into the centre of our consciousness, in spite 



ATTENTION 6 1 

of our effort to keep them from entering. This form of atten- 
tion should not be confused with non- voluntary attention, 
for while involuntary and non-voluntary attention are alike 
in the fact that it is the force of the stimulus itself rather 
than any purpose in the mind that starts the attention proc- 
ess, involuntary attention is always complicated with effort 
against, or away from, the incoming stimulus or topic of 
thought which captures the attention. However, it is evi- 
dent that the things that do succeed in taking the citadel of 
our consciousness by storm are the things that awaken our 
spontaneous or non-voluntary attention. From this point of 
view involuntary attention is the old non-voluntary atten- 
tion come back to us. 

Another classification of the forms of attention which has 
been even moie popular than the preceding one is that which 
divides attention into — 

1. Passive attention, 

2. Active attention. 

Passive attention corresponds very closely to non-volun- 
tary or spontaneous attention. When an intense or sudden 
stimulation forcibly breaks into our consciousness, or when 
some insistent idea takes possession of us, we are, in respect 
to the initiation of the attention process, passive. We do 
not start the process; something outside the self commands 
it. The term passive, however, is a misnomer if it is used to 
describe the attention process itself, for all attention is active 
once it is set up. "Passive" refers only to the fact that 
attention may be determined by something which is out- 
side of the self, not that the attention process itself is pas- 
sive. 

Active attention, on the other hand, is self-determined, 
i. e., we take the initiative in starting and maintaining the 
process. It is really voluntary attention. When we attend 
because of some conscious purpose or plan in our mind we 
are active in initiating the attention process. Active atten- 
tion is always the result of effort and is attended by strain- 



62 PSYCHOLOGY 

sensations, while passive attention requires no effort on our 
part and is free from strain-sensations, at least in its initial 
stage. 

Passive attention may easily pass into active attention; 
e. g., the forcible presentation of some object may start a 
voluntary train of thought or an active examination of the 
object in conformity to some plan which we wish to carry 
out. 

Still another classification divides attention into — 

1. Sensory attention. 

2. Intellectual or ideational attention. 

This classification does not consider the attention process 
itself so much as the kind of material upon which the atten- 
tion works. 

Sensory attention is the attention we give to the object 
which stimulates the sense-organs. Its direction is therefore 
determined by our environment. Sensory attention is also 
in many cases non- voluntary and passive attention, but it is 
not coextensive with these forms. For it is evident that in a 
given environment we, ourselves, may be active in determin- 
ing the objects to which we give our attention, i. e., the sen- 
sations to which we attend. In this case sensory attention 
is coexistent with voluntary and active attention. Those 
cases of passive attention where memories or ideas force the 
attention lie, of course, outside of sensory attention. 

Intellectual or ideational attention is the attention we give 
in memory, imagination, judgment, reason; in short, in all the 
mental processes other than sensation and perception. Most 
of the cases of intellectual attention fall also under voluntary 
and active attention, although not all of them. For instance, 
in cases of attention set up by insistent or fixed ideas, atten- 
tion is both intellectual and non-voluntary, or passive. 

In much of our conscious life these distinctions between 
the forms of the attention are not present as absolute Hnes of 
demarcation. The forms of attention merge into each other 
or are present in one state of consciousness in varying degrees. 



ATTENTION 6^ 

Oftentimes it is impossible to determine whether we are 
attending because of some purpose in our minds, or because 
of the intensity of the outer stimulus. Both influences may 
be at work. Again, a state of consciousness is rarely, if ever, 
purely sensory, for every stimulus awakens intellectual proc- 
esses as well as sensory processes. What we are conscious of 
at any moment depends in varying degrees upon both our 
surroundings and upon the nature of our present and past 
experience. Sometimes the force of the environment pre- 
dominates, and sometimes the purposes and plans within us 
are uppermost in consciousness. 

From the genetic point of view these forms of attention 
represent stages in the growth and development of conscious- 
ness. Non-voluntary attention, passive attention, and sen- 
sory attention are, in large part, the first kind of attention to 
appear. How consciousness becomes clear and vivid in the 
beginning involves the problem of how we can be conscious 
of an outside world at all. At any rate, the fact remains 
that sense -stimuH acting upon a nervous organism force 
their way to consciousness, and this consciousness is the 
germ of attention. Whether or not they arouse clear and 
definite awareness at first, they certainly occupy the centre 
of what consciousness there is, and call out the native reac- 
tions of the organism. Bodily adjustments and sense-ac- 
commodations take place. Sensations of movement and 
simple feeling are awakened. The whole organism, mental 
and physical, is centred upon the stimulus. All the essential 
characteristics of attention are present. But it is a native 
or reflex attention, the attention which the organism gives 
because by virtue of its inherent nature it cannot do other- 
wise. The organism is so constituted that certain stimuli 
attract it spontaneously, i. e., without effort or constraint on 
its part. In this stage of development it is the character of 
the stimuli which determines the selection of attention, i. e., 
to what stimulus among the many which present themselves 
the organism will react. Stimuli of high intensities or of 



64 PSYCHOLOGY 

certain qualities, often-repeated stimuli, sudden changes, 
movement, the strange or novel, food and shelter stimuh, all 
these possess a native attraction and are, therefore, attended 
to. They have been significant signs in racial development 
and evolution, marking out the pathway of self-preservation 
for the individual organism. They were signs of dangers to 
be avoided or of advantages to be gained; so the tendency to 
react to them has become native and hereditary. 

A higher stage of development shows the organism able 
to retain and reproduce past experience. The organization 
of this experience into a system of self-experience, any part 
of which can be recalled, forms a new basis of control. As it 
acquires experience the organism becomes less and less sub- 
ject to the domination of outside stimuli. It is able to take 
matters into its own hands, or, we might say less figuratively, 
the acquisition of new experience is determined by the na- 
ture of the old experience explicitly reproduced and formu- 
lated into purpose, plan, or desire. Or, to put the same 
matter in another way, the old experience assimilates the 
new. What we attend to in this stage of development is 
determined by the experience we can reproduce from past 
states of attention. Effort and strain-sensations appear as a 
result of sensory and bodily adjustments we consciously 
make. Moreover, the effort appears as self-effort, because 
it follows or accompanies the conscious plan or purpose 
within the mind. We now attend because we will to attend. 
This is voluntary attention, active attention, or intellectual 
attention. It has grown directly out of the preceding stage 
of non-voluntary, passive, or sensory attention^ in so far as 

1 It has already been noted that sensory and intellectual attention are not 
coextensive with non-voluntary and voluntary attention. Part of sensory 
attention may come under voluntary attention; e. g., one may voluntarily 
attend to some sense-stimulus. Or intellectual attention may be non-volun- 
tary after voluntary attention has been transformed into acquired non-volun- 
tary attention; e. g., the student may attend without effort to his exercises in 
logic after he has thoroughly mastered them. However, in the beginning non- 
voluntary attention is largely sensory attention. 



ATTENTION 65 

these last forms of attention are evoked by the character and 
force of external stimuli. 

A still higher degree of development appears when vol- 
untary attention in any particular field loses its effort and 
self-constraint and becomes spontaneous. This represents 
the highest stage of mental development and efficiency. 
With respect to the attention it may be designated as ac- 
quired spontaneous. In time we come to attend spontane- 
ously, and in quite as free and unconstrained a manner as 
in native spontaneous attention, to our studies and our work. 
Art, literature, and science may become second nature. 
They may appeal to us and challenge our attention unaided 
by any effort on our part. 

In the order of development, then, consciousness first 
shows itself as native or reflex attention. Out of this develops 
effortful or voluntary attention, representing the stage of self- 
growth and self-development. Then comes acquired spon- 
taneous attention, representing the stage of self-mastery and 
achievement. 

If now we review all the forms of the attention we shall 
ind that there is one characteristic that is universally pres- 
ent. We refer, of course, to the characteristic of clearness. 
However attention may be determined — by the external 
stimulus, by conscious purpose, or by sensory or intellectual 
activities — the attention itself is clear consciousness, i. e., in 
attention we are more keenly conscious of some objects than 
of others, of some topics of thought than of others. 

Clearness must not be confused with high intensity or 
opposed to low intensity of stimulation. A low degree of a 
sensation may be perfectly clear in consciousness, or a high de- 
gree may not be attended to at all, /. e., it may not be clear. 

For instance: the pop of a tiny firecracker may be per- 
fectly clear in consciousness, while the boom of the cannon, 
although present in consciousness, may not be attended to 
and therefore may not be clear. The sound may have a high 
degree of intensity but a low degree of clearness. It is true 



66 PSYCHOLOGY 

that high intensity usually attracts attention and becomes 
clear, and that low degrees of intensity escape attention, but 
clearness and intensity are different attributes of conscious- 
ness. Whether attention increases the intensity of a sensa- 
tion or not, e. g., whether a continuous sound of constant 
objective intensity changes its intensity when we attend to 
it, is a question at present in dispute.^ It is evident, how- 
ever, that if there is any change in the intensity of presenta- 
tion when it reaches the focus of attention, the change is so 
slight that it escapes ordinary observation. 

It is a common belief in popular thought that the degree 
of attention is proportionate to the amount of effort expended 
in attending. The more effort we put forth the higher the 
degree of attention. This is true only within very narrow 
limits. In voluntary attention it requires effort to direct 
and hold the attention, and for a short time the degree of 
attention increases with the amount of effort. But in the 
higher degrees of attention, absorbed or rapt attention, there 
is no observable effort at all. If one becomes deeply atten- 
tive all effort to attend disappears. This is true in all cases 
of acquired spontaneous attention. A better measure of the 
degree of attention is the despatch and efi&ciency with which 
certain unfamiliar tasks are performed; e. g., the time required 
to learn a certain number of nonsense-syllables or the accu- 
racy and the time required to cross out the "a's" on a page 
of printed matter. Another measure is to note the strength 
of a distracting stimulus necessary to produce a decrease in 
efficiency with which one performs a task requiring close 
attention, and use that as a measure of the degree of attention. 

Still another method is to take, as a measure of attention,^ 

^ A minimal degree of intensity which lies just below the threshold of non- 
attentive consciousness may be raised above the threshold when the attention 
is turned upon it, i. e., one can hear the ticking of a clock when attention is 
given to it, while without attention it is inaudible. This may not be due to an 
increase in intensity, however. 

^Oehrn: " Experimen telle Studien zur Individualpsychologie," Psyche A^- 
beilen, I. 



ATTENTION 67 

the variations which we make in a series of accurate measure- 
ments under the same conditions. Say, for instance, one is 
measuring the length of a screw to thousandths of an inch, 
and several series of ten measurements each are made. It is 
evident that the higher the degree of attention given to any 
series of measurements the less the variation in the individ- 
ual measurements will be. The mean variation, or the aver- 
age departure from the average measurement in any series 
would be an indication of the degree of attention given in 
the series. In some series the variation would be small, in 
others large, and since the variations must be in the mental 
factors, we can reasonably suppose that the most important 
factor — attention — is the variable element. Obviously none 
of these methods measures attention itself. 

What is commonly spoken of as inattention is not a state 
of attention at all, but absolute non-attention. When we 
say that a schoolboy is inattentive to his lessons it is often- 
times true that he is deeply attentive to something else — the 
drawing of the teacher he is making or the bent pin that he 
intends placing on the seat of his enemy across the aisle. 
The enterprise in which he is engaged has completely dis- 
placed the lesson. There is, however, a positive state of 
attention which has inappropriately been called inattention. 
It is attention of a low order and exists in the general forms 
of wandering attention and dispersed attention. In wandering 
attention consciousness is abnormally unstable, flitting from 
one thing to another so rapidly that it is inefficient. In dis- 
persed attention objects and ideas do not stand out clearly 
and distinctly. Mental states are not focalized sharply, and 
so consciousness is blurred and hazy. These forms of atten- 
tion are frequently the signs of inanition, anaemia, a general 
lowered bodily condition, fatigue, or even of mental disease. 

Neural Basis of Attention. — If now we ask what the brain 
conditions are that are concomitant with clear and vivid 
states of consciousness, we are forced to theorize, for the 
physiological facts concerning the neural activities in the 



68 PSYCHOLOGY 

brain areas during consciousness have not yet been made 
out. We may fairly assume, however, that definite states 
of consciousness involve definite activities in certain brain 
centres; that the neural excitement in these centres is for the 
moment raised above that in other centres; that changes in 
attention correspond to changing areas of excitement or ten- 
sion in the brain. Now, we have seen that there are in gen- 
eral two factors which determine the direction of attention: 
(i) the nature of the external stimulus (bright lights, loud 
and sudden sounds, etc.), and (2) the nature of consciousness 
itself (effect of past experience, conscious plans and purposes, 
and ideas present in the mind). If some external stimulus, 
by virtue of its character, forces the attention, we can con- 
ceive the neural activity as working upward from a lower 
level or lower unit to a higher level or higher unit of nervous 
activity; i. e., the stimulus first raises the activity in a par- 
ticular sense centre above that in the other parts of the brain, 
and then drains off into, or involves the activity of, a higher 
neural unit or level which has previously been associated 
with the activity of the sense centre. The particular way 
we may attend to the given stimulus, the way we perceive it, 
is determined by the way we have perceived it in the past, 
and by the nature of consciousness at the time; e. g., the 
way in which I attend to the ringing of a bell outside — 
whether I perceive it as a street-car bell or as that of a baker's 
wagon depends upon my past experiences and my present 
surroundings. 

This means that at any moment certain brain centres are 
more susceptible than others. Some authorities hold that 
this greater susceptibility of some centres over others is due 
to facilitation, others think that it is due to inhibition of 
rival centres, and still others are of the opinion that both 
processes are at work. Facilitation means that the action in 
one brain centre (in the case cited probably a higher centre) 
increases the action in another centre. Inhibition means 
that the action in the centres not involved in the attention- 



ATTENTION 69 

consciousness is lessened or blocked by the action of a higher 
centre. Thus if I attend to the bell as that of a street-car, 
the centre involved in "street-car perception" is facilitated, 
and the centre corresponding to "baker's wagon" is inhib- 
ited. 

In the case where attention is determined by conscious 
purpose or plan, where we select one from several presented 
stimuli, we may conceive of the neural activity as working 
downward from higher units, and facilitating the action in 
the centres involved in the particular attention-conscious- 
ness, or as inhibiting the action of all other centres. Thus if 
I determine to listen to the faint strains of a distant street- 
organ rather than the nearer and louder noises of the street, 
certain centres are facilitated and all others are inhibited or 
blocked for the moment. 

Whether there are definite brain centres whose function 
it is to control these processes of facilitation and inhibition 
in attention, or whether any part of the higher brain may so 
act, is not known. It has been suggested that the so-called 
associational areas in the frontal lobes of the cortex are alone 
responsible for the facilitations and inhibitions in the play of 
attention-consciousness. Pathology has determined the fact 
that lesions in this part of the brain involve impairment of 
the attention especially. Comparative neurology shows that 
the size of these frontal areas goes hand in hand with the 
development of attention. We also know that in very young 
children, before sustained attention is possible, the frontal 
areas are not yet matured — that the nerve-fibres in this area 
have not acquired their myelin sheath, and are not, therefore, 
ready to function. 

However, in view of the paucity of detailed facts in the 
anatomy and physiology of the nervous system, we must 
suspend judgment concerning the neural basis of attention. 
It is all very vague and indefinite as yet. We can only hope 
that the rapid development in these sciences will throw more 
hght upon the question. 



70 



PSYCHOLOGY 





Fig. 32. 



Shifting of Attention. — ^We have aheady noted the chang- 
ing aspect of consciousness in attention. No mental content 
remains clear long — it rises and falls intermittently. This 

changing of attention is observ- 
able in topics of thought in- 
volving the higher mental proc- 
esses, memory, imagination, 
judgment, et cetera; in the per- 
ception of objects, and in mini- 
mal sensations coming from stim- 
uli of very low degree of intensity, 
i. e., sensations which lie just on 
the lower threshold of conscious- 
ness. If we try to fix some one 
topic of thought, we find it im- 
possible to hold any one aspect 
of it clearly in consciousness for 
any length of time. Thinking of 
one thing means that one after another of its aspects be- 
comes clear in rapid succession. The content of focal con- 
sciousness is always changing. The same fluctuations occur 
when we attend to objects. This 

is illustrated in the perception of ^^ ^^ ^^ ^P 
ambiguous figures. If we look at 

Figure 32, we perceive it as a card- ^^ ^^ ^^ ^^ 
board bent toward us, changing ^^ ^^ ^^ ^^ 
the next instant into a cardboard 

bent away from us. These two ^^ ^^ ^P ^P 
aspects of the figure alternate in 

consciousness. ^^ ^^ ^^ ^^ 

Observe the changing percep- ^^ ^^ ^^ ^^ 
tions of Figure 33 : It may appear Fig. 2,?,- 

as four lines of horizontal dots; or 

four lines of perpendicular dots; or as diagonal lines of dots; 
or as four squares; or as two squares, a smaller one included 
in a larger one; or in various other arrangements. 



ATTENTION 



71 



A special case of the fluctuation of perceptions is seen in 
binocular rivalry. Hold the open hand up before the right 
eye, select some object in the room that is screened entirely 
from the right eye but is in plain view of the left eye. Fix 
the attention on the object and it will apparently be seen 
through the hand. Part of the time it will stand out clear 
and distinct, part of the time it will be indistinct or even 
disappear completely, displaced by the perception of the 




Fig. 34. 



hand that lies between you and the object. The explanation 
is in the fact that part of the time you see more clearly with 
one eye and part of the time with the other. If a stereoscopic 
card is prepared with one-half-inch colored squares, red for 
the right eye and green for the left eye, and is then placed 
in the stereoscope, the red square is exposed only to the right 
eye and the green square only to the left eye. Under these 
conditions both squares seem to occupy the same position in 
the visual field, but only one of them is present in conscious- 
ness at a time. They alternate in a continuous rivalry, first 
one and then the other taking possession of consciousness. 
The periods of fluctuation vary slightly in duration with dif- 
ferent subjects, but they average about two seconds in length. 
Now we find that the length of time that one of these colored 
fields remains clearly in consciousness is influenced by the 
same factors that accompany attention. If one field is more 
intense than the other it remains in consciousness longer. 



72 PSYCHOLOGY 

Likewise, if one field has more complexity (lines and figures 
drawn upon it), or if eye movements or adjustments are 
made in conformity to the lines, or if one field is more strik- 
ing in novelty, or is more pleasing, it remains in conscious- 
ness longer than the other. ^ 

Hold an ordinary envelope between the eyes close to the 
face so that the circle (Figure 34) is cut off from the right eye. 
Fixate the square and the circle will disappear and reappear. 

The same phenomenon can be observed where one object 
is in the margin of the visual field, and another in the central 
portion. 



Fig. 35. 

Fixate the right dot, which should be placed directly in 
front of the right eye and about four inches away; look at it 
steadily for some time. The left dot will disappear and re- 
appear. 

When the attention is turned to continuous minimal 
stimuli the sensations resulting from them appear inter- 
mittently in consciousness. Periods of clearness and periods 
of obscureness or total disappearance can be observed. If, 
for example, the attention is fixed upon a very faint gray line 
just discernible upon a white background, it will remain in 
clear consciousness only a short time, disappearing and reap- 
pearing. Masson's disc is a simple illustration of this. 

A still simpler way to get the fluctuation is to fixate some 
spot on the wall that is barely visible. Faint auditory stim- 
uli (the faint ticking of a watch or the sound of a stream of 
fine sand falling on a blotting-pad) are also intermittently 
clear and unclear. In the case of faint pressure, gustatory, 
and olfactory sensations, fluctuation is not as evident. Taste 
and smell sensations do change in clearness, but since it is 
impossible to get a constant stimulus in these cases the 

' Breese: "On Inhibition," in Psych. Rev., Mon. Sup. III. 



ATTENTION 



73 




changes might be due to changes in the stimulus. Inhala- 
tion and exhalation are constantly changing the intensity of 
the stimulus in the one, and the varying chemical changes of 
food in the other. Pressure-sensations sometimes show a 
less observable fluctuation, and 
here the varying blood-pressure 
may change the effect of the stim- 
ulus, too. In fact, it has been 
claimed by some that all these 
fluctuations in perceptions and 
minimal sensations are not due to 
the attention at all, but to the 
accommodation of the sense- 
organs, and no doubt this has 
much to do with it. The lens of 
the eye changes its curvature pe- 
riodically, thereby changing the 
sharpness of the retinal image. 
The muscles of the ear contract 
and relax, varying the tension 
of the drum. Moreover, the pe- 
riods of oscillation in conscious- 
ness have been observed to corre- 
spond to these changes in accommodation in the sense-organs. 
So the question whether the shifts in consciousness are 
due to changes of accommodation in the peripheral sense- 
organs or to "fluctuation of the attention" is pertinent. 
Against the periphery theory has been offered the fact that 
fluctuations in visual sensations have been observed in cases 
where the muscles of the lens and pupil have been tempo- 
rarily paralyzed by atropin; also where the lens has been 
removed by operation. In cases where the drum of the ear 
has been destroyed, fluctuation occurs in auditory sensations. 
But this is not conclusive. The absence of the lens of the 
eye does not preclude the possibihty of fluctuation of sensi- 
tiveness to light-stimuli in the retina, the real sense-organ of 



Fig. 36. — -Masson's disc. 
When a disc of this kind is 
rotated, the short black 
lines give a series of faint, 
gray rings which grow fainter 
toward the circumference. 
The outer rings are barely 
visible. Fixate one of the 
faintest rings and it will 
disappear and reappear peri- 
odically. 



74 PSYCHOLOGY 

vision. There is reason to believe that the delicate nerve- 
endings in the retina undergo rapid chemical changes, and 
that these changes affect their sensitiveness. This might 
well account for the fluctuation of minimal light-sensations. 
Likewise, there may be other sense-organ adjustments in the 
ear than those of the drum, and they may account for the 
fluctuations of minimal auditory sensation. It is therefore 
doubtful whether these fluctuations are due to changes in 
attention or to end-organ adjustments. In some cases we 
are reasonably sure that they are due to the latter. 

For instance, in the case of the alternating red and green 
squares in the stereoscope, if, when I give my attention to the 
red square, the green square displaces it in sensory conscious- 
ness, I may still be thinking about the red square, attending 
to its quality, size, et cetera, so that the change in conscious- 
ness is not a change of attention. What really happens in 
this case is that part of the time I am attending to the sen- 
sory perception of the red square, and part of the time to its 
memory image. On the other hand, the green square may 
not occupy clear or attention-consciousness at all. When the 
green square is in consciousness the mental image of the red 
square is still clear, while the sensory experience of the green 
square is marginal. In the case of the disappearing faint 
gray ring of Masson's disc, I may still continue to attend to 
it after the gray ring itself has disappeared, by holding it in 
mind as a mental image. In other cases of minimal sensa- 
tions where the sense-organ is not supplied with delicate 
movements of accommodation, as, for instance, in very light 
pressure-sensations, attention is able to maintain itself with- 
out change for very much longer periods. 

Physiologically there are two factors to consider in these 
changes of consciousness: (i) the sense-organ activity and 
movements of accommodation, and (2) the central or cortical 
activity in the brain. Changes in attention are due to 
changes in the central brain activity — fatigue in the cortical 
cells, changes in blood-supply, anabolic and catabolic proc- 



ATTENTION 75 

esses, et cetera. Now, while the central activities in the 
brain are sometimes the result of the nervous impulses 
from sense-organs, they may at other times be independent 
of them. The central neural activities corresponding to 
attention must be conceived as including larger brain areas 
than the areas involved only in the reception of sense-stimu- 
lation and, when once set into action, as continuing, even 
though the sense-organs are inactive. For instance, if I 
attend to a certain book on my desk, my attention may 
involve more than the brain activity in the visual centres. 
Past associations and consciousness of the relationship to 
other objects may be present. If the book is removed from 
my sight I may go on attending to it. Or if an inkstand is 
put in its place I may still attend to the book and at the 
same time be conscious of the inkstand. But in this case the 
inkstand is not in the focus of attention. So we infer that 
the brain activities corresponding to attention-consciousness 
involve larger areas than those corresponding to mere sensa- 
tion or perception. We conclude, therefore, that attention 
may change with the changes of sense-stimuli or may act 
independently of them. Shifting of the attention involves 
more factors than those involved in the fluctuation of mini- 
mal sensations or in the rivalry of objects presented to the 
sense-organs. While attention cannot hold itself indefinitely 
to one thing, it is not limited so far as its maximum duration 
is concerned to the very short periods which characterize the 
fluctuation of minimal sensations, i. e., four to eight seconds. 
If we keep in mind the fact that the real function of 
consciousness, in all stages of development, has been to aid 
the organism in its adaptive adjustments to its environment, 
we can see why it is the nature of attention to shift. In 
order to survive, the organism has been forced to react quickly 
to a rapidly changing environment. One object after an- 
other has presented itself, and to each one in turn bodily 
adjustments had to be made. Presentation of an object, 
recognitiori of it, adaptive reaction, presentation of another 



76 PSYCHOLOGY 

object, recognition of it, another reaction, and so on in an 
ever-changing series of presentations and reactions, with con- 
sciousness mediating between them — such has been the his- 
tory of development. Now, each recognition and adaptive 
reaction has required only a short space of time. Conscious 
life has developed under the constant pressure of a changing 
environment, and so it has come about that ordinarily a 
simple flash of consciousness is all that is required to take 
in any given situation and meet it by making the proper 
reactions.^ 

Range or Span of Attention. — How many things can we 
attend to at once? Common sense says that we can attend 
only to one thing at a time. Careful experiment, however, has 
proved this to be untrue. Yet it is true that in every-day ex- 
perience attention is occupied only by a single object or topic 
of thought, but this does not represent the ability of atten- 
tion in this respect, especially in the perception of objects. 
It has been found that when simple objects are presented 
simultaneously to the eyes, from four to six single objects 
can be apprehended at once. If simple sounds are presented 
successively, as in the taps of a metronome beating four 
times a second, six to eight taps can be perceived as a unit 
without counting the single taps. In the case of the simul- 
taneous presentation of simple objects the length of time in 
which the objects are exposed to the eyes must be very short 
— short enough to prevent more than one act of the attention. 
The time exposure should be just long enough for the sub- 
ject to perceive clearly a single one of the objects. This time 
period varies from o.oio to 0.200 seconds. It is necessary, 
therefore, to use an accurate time-exposure apparatus, called 
the tachistoscope, for these experiments, although rough 
experiments may be carried on by means of an ordinary drop- 
screen. 

The result of experimentation has also shown that atten- 
tion can take in complex objects quite as easily as simple 
1 See Angell: " Psychology," 4th ed., p. 94. 



ATTENTION 77 

objects. For instance, it was found that as many words 
as single letters can be apprehended in one pulse of the at- 
tention, i. e., three to six words. Likewise, familiar groups 
of lines, dots, or objects may be attended to as a single im- 
pression or unit; and as many single groups can be perceived 
in one grasp of the attention as single objects. This means 
that when we attend to the single group the attention is not 
occupied with the single objects which make up that group. 
When we attend to a word as such, we do not attend to the 
single letters making up the word, but on the other hand we 
treat the word as the unit of attention. We may even treat 
phrases or sentences as units of attention. The same holds 
true in the apprehension of successive sounds. In one pulse 
of the attention some subjects can perceive four groups of 
four taps of the metronome, i. e., sixteen single taps. In 
this case the attention is not occupied with the single taps, 
but with the groups. This illustrates the fact that an object 
may be attended to in different ways. Thus sixteen regular 
successive taps of the metronome may be perceived or at- 
tended to as sixteen distinct and separate sounds, with full at- 
tention given to each sound; at another time as four groups 
of sounds, and at another time as a single group of four 
groups. In the first case there are sixteen, in the second 
four, and in the third one act of the attention. 

This grouping of objects is possible because we build up 
higher and higher units of perception, as a result of education 
and training. Starting first with the discrete sensory units, 
we soon learn to associate them into groups which we appre- 
hend as single units. At first the schoolboy may attend to 
each single letter, but when the letters become associated 
attention moves on to the word. The letters in the word are 
present in consciousness, but they are marginal, i. e., they 
are not in the clearest part of consciousness, for attention is 
occupied with the word or higher unit. Further training 
makes still higher units possible. The words may be grouped 
into phrases and sentences which are apprehended singly. 



78 



PSYCHOLOGY 



Effect of Attention. — In a general way we may say that 
attention increases the efficiency of consciousness. When 
the attention is turned expectantly in a certain direction 
everything is in readiness to receive the stimulus, the end- 
organs are accommodated, and the central brain centres are 
prepared in advance by virtue of the mental image of the 
expected stimulus. This increases the rate of entrance of 
the stimulus, and lowers the sensation threshold, i. e., in- 
creases the sensitiveness of the nervous organism. The fol- 
lowing simple experiment will illustrate the latter point. If 
cardboards upon which geometrical figures (squares, circles, 
or triangles) are drawn are presented to a subject at a dis- 
tance at which the figures cannot be recognized, it will be 
found that, if the cardboards are brought slowly nearer to 
the subject, a distance can be determined where the figures 
will be just clearly recognized. Now this distance will be 
greater when the subject is told beforehand what figure is 
upon the card than it will be when he is not told what figure 
is upon the card. 

The following table gives the results of five tests under 
each condition: First condition, the subject did not know 
what figure was approaching; second condition, the subject 
knew what figure was approaching. 



First Condition 



Second Condition 



Figure recognized at. 



Average distance recognized . 



15.7 feet 
16.0 " 

15.8 " 
IS. 8 " 
18.0 " 

16.8 feet 



19 . 9 feet 

7 " 
16.8 " 
23 
16 



19 



S feet 



Here, when attention was given to the approaching stimu- 
lus, the distance at which it could be recognized was increased 
2.7 feet. Likewise the threshold of auditory sensations is 
lowered by active attention. The same subject whose rec- 



ATTENTION 79 

ords are given above could hear the ticking of the laboratory 
watch (one he had never heard before) only when it was 
brought within a distance of ten feet from his ear. But when 
he had once heard it distinctly and attended to its peculiar 
sound he could hear it thirteen feet away. 

The latent period of perception, i. e., the time between 
the presentation of the stimulus to the sense-organ and the 
recognition of it in consciousness, is shorter in attention than 
it is in marginal consciousness. Every stimulus requires 
some time to develop in consciousness. It is, of course, a 
relatively short period, and is measured in thousandths of a 
second. This developing period goes on most rapidly in the 
focus of attention. Of two simultaneously given stimuli the 
one that is voluntarily attended to arrives in consciousness 
first. If we should attend closely to the revolving pointer of 
a compHcation clock, ^ and attempt to locate the exact posi- 
tion of the pointer when the bell strikes, we should find that 
the resulting sound, not being in the focus of attention, will 
require a longer time to develop in consciousness than the 
visual appearance of the pointer on the dial. Consequently 
the sound will be retarded in reaching clear consciousness. 
If, when the attention is on the pointer, the bell is arranged 
to sound when the pointer is at a given position on the dial, 
the sound will not reach consciousness until the pointer ap- 
pears to the observer to be some degrees beyond. With the 
attention fixed upon the visual stimulus, the auditory sen- 
sation lags behind in consciousness. The visual sensations 
ripen more rapidly than the auditory sensations under these 
conditions, so that when the more slowly developing sound- 
sensation reaches consciousness, the visual perception of the 
pointer several degrees ahead on the dial has developed into 
clear consciousness. The sound and the pointer appear 

^ The complication clock is a graduated dial around which a pointer revolves 
from six to ten times per minute. The clock is connected, usually electri- 
cally, with a bell which may be made to strike a single note at any given posi- 
tion of the pointer. 



8o PSYCHOLOGY 

simultaneous at the advanced position of the pointer, i. e., 
there is a negative time displacement of the sound. If, now, 
attention is fixed upon the sound, the pointer, being in the 
margin of consciousness, will lag behind and will appear to 
be several degrees back of the given position when the bell 
sounds, i. e., there is a positive time displacement of the 
sound. 

Very common illustrations of this retardation of stimuli 
which are not attended to, but which have been received in 
marginal consciousness, are found in every-day life. If one 
is intently absorbed in reading or in deep meditation, it 
may happen that he does not notice the striking clock until 
the third or fourth stroke, and then become fully conscious 
that he has heard it striking from the beginning. The small 
boy who is busily engaged in play probably tells the truth 
when he says to his mother, after she has called him: "Mother, 
I didn't hear you until you had called the second time." 

Attention increases the speed of movement. If, when a 
visual or auditory signal is given, a subject attempts as 
quickly as possible to make a simple movement, such as 
pressing down a telegraph-key, the reaction can be made 
more quickly if attention is focussed upon the movement to 
be made. Obviously, attention may be given either to the 
signal or to the movement. If attention is given to the 
signal, the time of reaction is termed "sensory-reaction time"; 
if, on the other hand, attention is given to the movement, 
it is "motor-reaction time." In most cases the "motor- 
reaction time" is shorter than the "sensory-reaction time" 
by from 0.080 to o.ioo seconds. The former is about 0.140, 
while the latter is about 0.240 seconds. However, when the 
movement becomes perfectly familiar or habitual, the differ- 
ence between these forms of reaction tends to disappear. In 
general, we may say that the time of any conscious reaction 
is lessened when attention is given to the least familiar or 
habitual elements in it. 

Since attention is the condition of all clear and vivid im- 



ATTENTION 8 1 

pressions, its effect upon memory is obvious. That which is 
attended to closely is more likely to be retained and recalled 
afterward than that which is not attended to. Further- 
more, the order of recall is determined by attention. For 
what is remembered depends upon what is in the focus of 
attention at the moment. This not only determines the 
direction which the memory takes, but it also determines the 
sequence of thoughts in imagination, Judgment, and reason — 
in short, in all consecutive thinking. 

Motor Accompaniments of Attention. — We have had occa- 
sion several times to refer to the fact that attention is accom- 
panied by certain bodily reactions. In fact, the connection 
between the motor activities of the body and attention is so 
intimate and constant that some psychologists hold that 
attention is fundamentally a motor phenomenon.'^ The at- 
tention we give in looking at an object, according to this 
view, is really and essentially nothing more than the turning 
of the body toward it, the accommodation and converging 
of the eyes upon it, the changed respiratory movements and 
heart action which take place when we attend to it. Or, 
more properly, the effect of these motor activities in con- 
sciousness is the only differentia between attentive conscious- 
ness and non-attentive consciousness. This theory would 
take the accompaniments of attentive consciousness as its 
cause. Although we cannot accept the theory that atten- 
tion is essentially the effect of a set of motor accommoda- 
tions, we must nevertheless recognize their importance in 
attention. For no state of attention exists that does not 
show definite motor adjustments pecuHar to it. No one can 
give attention without manifesting signs of bodily reactions 
toward the object of attention. The accommodation of the 
sense-organ, the tension of the facial muscles, the strained 
motor attitude of the body, the slowed respiration and heart 
action are all marks of attention. It is doubtful if attention 
and a general relaxation of the muscles can take place at the 
iRibot: "Psychologie de I'attention." 



82 PSYCHOLOGY 

same time. These motor reactions have their part to 
play in making the content of consciousness clear and 
definite. 

Both the voluntary and the involuntary reactions are m- 
volved in attention. For instance, if we attend to a visual 
object, the turning of the head and eyes toward the object 
and the partial suspension of respiration may be voluntary, 
but the adjustments of the lens and the pupil of the eye and 
the capillary. change in the blood-vessels are involuntary, or 
reflex. The motor reactions in attention, therefore, repre- 
sent the whole organism, involving both the native and the 
acquired reactions. 

Involuntary movements of the body are often sufficiently 
observable to the degree that they may be taken as indica- 
tions both of the direction and nature of attentive conscious- 
ness. Many so-called mind-readers (really muscle-readers) 
take advantage of the involuntary movements of their sub- 
jects in detecting the nature and direction of attention. 
Especially is this true in cases where the "mind-reader" is 
attempting to find a hidden article, the location of which is 
known and kept steadily in mind by the subject. By watch- 
ing the subject closely or by holding his hand as he leads him 
about the room, the "mind-reader" can detect involuntary 
movements of hesitation and negation, of acceptance and 
consent, which give clews to the position of the object. We 
may note these motor impulses in ourselves. If we think of 
an object directly overhead, slight involuntary movements 
of the head or eyes toward the object are observable. If we 
think of the word bub-ble, movements of the lips can be de- 
tected. If we think of biting into the pulp of a raw lemon, 
we are seized with involuntary shudders. Such move- 
ments are usually not noticed until attention is called to 
them. 

Now, if we canvass all the movements that characterize 
attention we shall find that they fall into four classes : ^ 
^ See Pillsbury: "Attention," chap. II, 



ATTENTION 83 

First : Movements of accommodation of the sense-organs, 
the purpose of which is to give a clearer impression of 
stimuh.^ 

Second: Movements of the voluntary muscles, expressly 
made for the purpose of taking advantage of the objects or 
ideas attended to in a way that has previously been found 
useful to the organism. 

Third: Overflow movements in the voluntary muscles.- 

Fourth : Reactions of the respiratory and circulatory mus- 
cles. The pulse and respiration curves show marked changes 
with the changing states of attention. The blood-pressure in 
the capillaries also varies with the attention changes. 

These motor accompaniments are present not only in 
sensory attention (attention to objects presented to the 
senses), but, as we have already seen, they are also found in 
intellectual or ideational attention, attention given to mem- 
ories, images, and ideas. The memory image of a green per- 
simmon will cause the same puckering of the mouth, although 
perhaps in a lessened degree, which the fruit itself caused 
when actually experienced. To form the mental image of 
an object behind us involves the tendency to turn the head. 
The idea of coldness is accompanied with incipient shivers. 
In short, all our clear and vivid thoughts are accompanied 
by motor reactions that are more or less appropriate to them. 
Put in a way which will cover the facts of both sensory and 
ideational attention, we may say that all clear consciousness 
involves motor activity. 

Feeling of Effort in Attention. — The fact that we experi- 
ence effort and strain in voluntary attention leads naturally 

1 This should include the movements of the body which place the sense- 
organs in a more advantageous position with respect to the stimulus. These 
movements may be voluntary and so differ from the involuntary accommoda- 
tions of the sense-organs, but their purpose is the same, i. e., to give a clearer 
impression of the stimulus. 

2 It has been suggested that these overflow movements serve to keep the 
neural activity going in the same channel and thus inhibit the effect of dis- 
turbing stimuli. See Angell: "Psychology," 4th ed., p. loi. 



84 PSYCHOLOGY 

to the assumption of an activity back of the contents of 
the attention-consciousness — a something that decides what 
things are to be attended to. Effort and strain are assumed 
to be the effort and strain of the attention itself. Now, care- 
ful observation reveals the fact that the effort and strain 
come from the motor accompaniments of attention, and not 
from attention itself. The contracted brow, the set teeth, 
and other bodily muscular tensions, together with the adjust- 
ments of the sense-organs, give a diffused mass of strain- 
sensations. They might very readily be taken in superficial 
observation for the activity of the attention. 

Interest and Attention. — Popular thought has some very 
decided views concerning the relation of interest to attention. 
For instance, it is supposed that interest precedes and leads 
to attention — that we attend because we are interested, not 
that we are interested because we attend. While this view 
contains an element of truth, it involves a confusion of 
thought that may be easily corrected if we consider what 
interest really includes psychologically. 

In the first place, interest, as we commonly use the term, 
includes attention. We cannot be interested without attend- 
ing. Interest, therefore, cannot exist and then attract atten- 
tion to it afterward, for the very reason that any state of 
consciousness that may be called interest has attention al- 
ready in it. Interest is a complex mental state comprised 
of a clear and vivid state of awareness (attention), accom- 
panied by feehng and conation (impulses to activity). When 
we are interested we are clearly aware of the object of inter- 
est, take a feeling attitude toward it, and are impelled to 
react in some way, i. e., approach or withdraw from the 
object. 

{Vivid awareness (attention). 
Feehng. 
Conation. 

The most important element in this complex is attention. 



ATTENTION 85 

There can be no real separation of interest and attention. 
In fact, interest is only another name for non-voluntary or 
spontaneous (both native and acquired) attention. The 
things that we are interested in are the things that attract 
the spontaneous attention. Moreover, the order of the de- 
velopment of our interests is the order of development of 
attention. First come our native interests — food, shelter, 
intense stimulation, bright lights, loud sounds, moving things, 
etc., and last of all, our acquired interests — art, literature, 
science, our professions, occupations, etc. Between the na- 
tive and acquired interests lies the stage of voluntary atten- 
tion. Our acquired interests rest mainly in those things 
with which we have become familiar through voluntary 
attention. 

Sometimes interest is used to signify only the affective 
elements in attention — the feeling of pleasure and satisfaction 
experienced with our states of awareness. We get pleasure 
and satisfaction out of the things that help us forward, and 
therefore we attend to these things. It is better to say that 
we get pleasure and satisfaction because we attend, for the 
pleasure and satisfaction are never experienced until after 
attention is given. If we go in quest of these interesting 
things, we must first attend to the memory images of them 
before our interest is awakened. 

From the genetic point of view interest follows attention; 
for it is not until after the organism gets a clear and definite 
awareness of the objects in its environment that it takes the 
attitude of interest toward them. Now, in the evolution of 
consciousness some states of awareness were accompanied by 
more feehng and more conation than others. These states 
of vivid awareness, with their accompaniments of feehng and 
conation, were the primitive states of interest. Certain 
things attracted attention, aroused feeling, and impelled to 
action. They were the things that were vitally beneficial 
or harmful to the organism. That is the reason they com- 
manded the attention, and also the reason they became in- 



86 PSYCHOLOGY 

teresting when attention was given. And so we have come 
to call the things interesting that we attend to spontaneously. 
We should not, however, forget that attention has created 
the interest. 



CHAPTER IV 
SENSATION 

Sensation as an Element of Consciousness. — When we 
examine our consciousness of the external world we find that 
it is very complex. Even the simplest thing has a large 
number of qualities. The rose has color, fragrance, form, 
and thorns, all of which may assail the different senses at 
the same time and are therefore present in our consciousness 
of it. We are never conscious of any one of these qualities 
alone. They always exist in combination. It is the busi- 
ness of psychology to analyze these complex experiences of 
the external world into their simplest elements, and to take 
account of them separately. 

The simplest elements into which we can analyze our 
cognitive consciousness are sensations. Such experiences as 
color, smell, pressure, pain, and taste, which we, as psycholo- 
gists, abstract from the larger conscious states in which we 
find them, and which we are unable to analyze into still sim- 
pler experiences, are sensations. If, for instance, we could 
attend to the redness of the rose alone, the color, abstracted 
from the form and material of the petals, from its relation 
to surrounding objects, from its position in space, from its 
unlikeness to the green leaves, would be a simple sensation. 
Sensations, then, are the immediate and unanalyzable ele- 
ments of cognitive consciousness. Or, as Professor James 
puts it, "Sensation is the immediate result of stimulations 
before further knowledge or past experiences are awakened. 
Sensation is the basis of all knowledge. A being without 
sense-organs of any kind could never know anything of the 
world about him." 

87 



88 PSYCHOLOGY 

Pure Sensations. — It is evident that "pure sensations " 
are psychological abstractions, the result of psychological 
analysis. They are never realized in actual experience. It 
is said that pure sensations are possible only during the very 
first experiences of childhood. Afterward stimuli arouse 
more than the sensations themselves. Past experiences, sug- 
gestions of familiarity, relations of likeness and unlikeness, 
meanings, all these and more come along with sensations. 
However, it is necessary in our study to abstract sensations 
from the complexes in which they appear, and treat them as 
though they existed independently of the combinations in 
which they are manifest. For example, the rose arouses not 
only the sensation of red, but also awareness of its position in 
space, consciousness of familiarity, and many other factors 
which involve revived past experiences. Just the sensation 
redness cannot exist alone. However, at times, we may 
have sense-experiences which approach the simple quality of 
pure sensations. If some one should explode a giant fire- 
cracker under my chair quite unexpectedly, the very fiirst 
brief instant of sense-impression I receive, before collecting 
myself sufficiently to have any suggestion as to the nature 
or position of the disturbance, would approximate a pure 
sensation. Immediately, however, as past experiences re- 
vive and mental syntheses begin to form, recognition both 
of the nature and the position of the disturbance would join 
with the simple sensation, making it a complex experience. 

In view of this fact it is evident that ordinary observation 
of mental life must be supplemented by scientific treatment. 
Unless we consider sensation as simple and elementary and 
capable of being isolated for purposes of study, no scientific 
analysis of our sensory experiences can take place. 

Physiological Basis of Sensation. — In all parts of the 
body, there are sensory surfaces supplied with sense-organs, 
which are connected by nerve-fibres with the sense centres 
in the brain. The vital organs, the articular surfaces, the 
muscle and tendon bundles, the skin, the mouth, the tongue, 



SENSATION 89 

and the nasal cavities, the ear, the retinal surface of the eye 
— all have their own specific sensory nerve-endings which 
connect through chains of nerve-fibres with the brain. Some 
of these sense end-organs are affected primarily by conditions 
existing within the body, while the others are affected by 
objects outside the body. Whatever afi^ects the sensory end- 
organs sets up nerve-impulses which are transmitted to the 
brain. Nerve- tissue possesses a characteristic known as 
irritability of nervous tissue, by virtue of which changes in 
one part of it are communicated to other parts. The sen- 
sory end-organs, connected as they are with the brain, form a 
rather extended system of reporting agencies which keep the 
central nervous system in touch with the happenings that 
are constantly taking place in the body and in the world of 
objects outside. 

The Nature of the Nerve-Impulse.^ — Just what happens in 
a nerve that has been stimulated and is transmitting impulses 
the physiologist is at present unable to say. It is, however, 
certain that some form of energy is set up in the sense-organs 
by the action of the stimuli. This energy is then trans- 
mitted over the nerve-fibres. There is, however, no means 
of deciding whether its nature is mechanical, chemical, or 
electrical. An interesting question arises as to whether the 
nerve-impulses in the nerve-fibres from different sense-organs 
are the same in quality, or whether these fibres carry differ- 
ent specific energies to the brain. No matter how the optic 
nerve is stimulated, either by the light falling upon the eye, 
or by an electric current passing through the forehead, or 
by a blow upon the head, or by pressing upon the eyeballs, 
the result is a sensation of light. Similarly, each sensory 
nerve, however stimulated, gives rise to its own appropriate 
sensation when its impulse reaches the brain centre. We 
may interpret these facts in two ways: Either each kind of 
sensory nerve carries different impulses, or all sensory nerves 
carry the same kind of nerve-impulses. In the latter case 
the different forms of sensation which they arouse are due 



go PSYCHOLOGY 

not to the impulses in the nerves themselves, but to the ac- 
tivities in the different brain centres. The first alternative 
is known as the theory of the specific energy of nerves. Mod- 
ern physiologists are inclined to deny this theory. They 
hold that the "specific quality" belongs not to the periph- 
eral nerve-impulses, but rather to the central brain processes. 
There is no physiological evidence of specific energies in dif- 
ferent sensory fibres. So far as we know, there is no differ- 
ence in kind between, for example, the impulses in the optic 
nerve and the impulses in the auditory nerve. On the other 
hand, it seems more reasonable to suppose that each sense- 
organ has a different mode of nervous action, and that its 
specific mode of action is transmitted to the brain by its 
nerve-fibres. However, in the present state of physiological 
knowledge, the question cannot be definitely answered. 

Evolution of Sense-Organs. — There are some reasons for 
believing that the highly developed special sense-organs are 
the result of evolution — that they have developed in the 
course of racial growth from the primitive sensitive epithelial 
cells in the skin. In man the tactile sense is the nearest ap- 
proach to the primitive epithelial sense in the lowest animal 
forms. The skin, or epithelium, is probably the earliest sense- 
organ. When, in the racial series, the differentiation from 
this primitive general sense toward the special senses began, 
it originated in a modification of the epithelial cells. These 
cells became elongated, with their peripheral ends turned 
toward the surface for the reception of the stimuli. From 
the other ends nerve-fibres were developed for transmitting 
impulses to other parts of the organism. Thus the sense- 
organs of smell, taste, and pressure were developed. Even 
in the cases where the sense-organs do not lie on the surface 
of the body, as in sight and hearing, the sensitive cells are 
developed from the epithelium. The auditory sense-organ 
of the higher animal forms may be traced back to an open 
auditory pit, like that of the crawfish. A higher form of the 
auditory pit is the auditory vesicle of the moUusk. Here 



SENSATION 91 

the auditory vesicle bears upon its surface sensitive epithelial 
cells which are centrally connected. Within the vesicle is an 
auditory ossicle held in place by hair-like cells. In the ver- 
tebrates the auditory vesicle has developed into the sacculus 
and the utriculus of the ear. From the sacculus there has 
developed a spirally wound tube, the cochlea, while from the 
utriculus have grown the semicircular canals in the ear of 
man. 

The sense-organ of vision has likewise undergone many 
transitional stages of development. The simplest form con- 
sists of a group of pigmented cells lining the walls of a de- 
pression in the skin. . These cells are elongated, with one 
end turned toward the Hght arid the other end drawn out 
in order to make proper nerve connections. Such a primi- 
tive eye is found on the tentacles of the limpet. A further 
development of simple eye-spots is found in some species of 
worms, where a light -concentrating apparatus has been 
evolved. The snail shows a still higher form. Here a 
simple retina with a protecting covering and a lens for 
focussing light-rays appear. The lens, however, is not suffi- 
ciently developed for forming images, so that the snail does 
not possess distinct vision. The next step is the perfecting 
of the lens, and where this has taken place there is close ap- 
proximation to the eye of man. 

In the tactile sense there has been a development from a 
sensitive epithelial cell provided with a hair shaft so placed 
that movement of the hair is communicated to the cell, to 
the tactual corpuscles of Meissner, a bulb-like formation of 
nerve-fibres found in the skin of man. The end-organs of 
cold and warmth have also been differentiated from the 
primitive tactile cells. 

The Stimuli. — A stimulus is any force that acts upon a 
sense-organ. The forces which make up the various stimuh 
usually come from objects outside of the organism, but in 
certain cases they arise within the organism itself. Physio- 
logical changes may liberate forces which act upon sense- 



92 PSYCHOLOGY 

organs and give rise to sensations. Most of the organic sen- 
sations are set up in this way. Hunger, thirst, organic pain, 
etc., are caused by physiological changes within the organism. 
The stimuli which affect the end-organs are innumerable, 
but they may be classified roughly into the following groups : 

1. Mechanical stimuli. 

2. Chemical stimuli. 

3. Thermal stimuli. 

4. Photic stimuli. 

5. Electrical stimuli. 

Mechanical stimuli consist in changes of pressure, such as 
those caused by objects coming in contact with the skin sur- 
faces, or sound-vibrations beating against the ear. Chemical 
stimuli come from the chemical changes going on in food sub- 
stances taken into the mouth, and possibly in odorous par- 
ticles or in gases affecting the nose. Thermal stimuli are 
changes in the temperature surrounding the organism. Photic 
stimuli are light-vibrations (supposed to be ether-vibrations) 
affecting the eye. Electrical stimuli seem to be able to affect 
most, if not all, of the sense-organs. 

With respect to their appropriateness or fitness to affect 
sense-organs, we may divide stimuli into adequate and inade- 
quate stimuli. Adequate stimuH are those to which the sense- 
organs are fully adapted, while inadequate stimuli are those 
to which the sense-organs are not adapted. Light is an ade- 
quate stimulus for the eye; air-vibrations for the ear; warmth, 
cold, and pressure for the skin; soluble substances for the 
taste sense-organs, and gaseous particles for the smell sense- 
organs. On the other hand, light does not affect the ear nor 
air-vibrations the eye. They are therefore inadequate stimuli 
in these cases. While a blow on the head or pressure on the 
eye may result in light-sensations, such stimuli are, neverthe- 
less, inadequate stimuli for the eye. In so far as a sense- 
organ is affected by inadequate stimuli, it gives rise to its 
own specific sensation. 

What the real stimulus is is a question which transcends 



SENSATION 93 

the limits of naive thinking. Ordinarily we are in the habit 
of considering the object we experience as the stimulus. But 
careful consideration will show us the error of this way of 
thinking. We are never conscious of the stimulus itself. 
Light-sensations are the result of the vibrations of some form 
of energy (supposed to be ether) which acts upon the rods 
and cones of the retina. Sound-sensations are set up by air- 
waves falling upon the sensitive parts of the ear. But we are 
never directly conscious either of the air-waves or of the ether- 
vibrations themselves. So, through all the senses, the real 
stimuli that affect the sense-organs and set up sensory ex- 
periences are always beyond our direct observation, and so 
are never experienced themselves. We can only infer their 
nature. What these various forms of energy in the mechan- 
ical, chemical, thermal, photic, and electrical stimuli are is 
a problem for physics to solve. This consideration naturally 
raises the question of the nature of the objects which we 
experience. Physically, of course, we say that they are dif- 
ferent forms of energy. But are they really what our expe- 
rience reports them to be? Do they exist as we experience 
them, or are they something entirely different? Or do they 
exist only as our experience ? Really, psychology is interested 
in and capable of deciding upon only one point raised in these 
questions. And that is that, whatever else the so-called ob- 
ject in the outer world is, it is at least my experience. 

A still more complex situation confronts us when we con- 
sider that between the stimulus and the sensation there 
stands another form of objective existence (the nervous proc- 
ess in the brain), of which we are not conscious. We cannot 
sense the brain processes, for the brain is insensitive to its 
own activities. Here, again, we see that sensation depends 
upon something (the brain process) that is itself beyond our 
direct observation. Some curious theories have been ad- 
vanced to explain how a material object is presented to con- 
sciousness. For instance, some of the earlier philosophers 
supposed that objects give off a kind of spiritual essence, or 



94 PSYCHOLOGY 

copy, which enters consciousness, and in this way objects 
reveal themselves to us. But we have overstepped the limits 
of psychology and are in the field of metaphysics. 

After-Eflfects of Stimulus. — The length of time which a 
stimulus acts upon the end-organ and the duration of the 
resulting sensation are not the same. With respect to the 
stimulus, the sensation is retarded. Sensation does not start 
the instant the stimulus begins to act upon the sense-organ. 
This is due to the inertia of the nervous mechanism. A brief 
period is required to set the neural machinery in action. 
Even after the sensation begins it does not reach its maximum 
at once. This fact cannot be observed directly, but can be 
demonstrated in the laboratory. If a light of a given inten- 
sity is allowed to act upon the eye intermittently, so that 
each period of stimulation is very brief, the resulting sensa- 
tion, although constant, is reduced in brightness, due to the 
fact that the stimulus acts for so short a time that the neural 
process is not raised to its maximum intensity. 

In addition to the initial retardation of sensation, there 
is another discrepancy between the time of the stimulus and 
that of the sensation, namely, that the sensation continues 
for some time after the stimulus ceases to act on the end- 
organs. This finds its explanation in the fact that the ac- 
tivity of the end-organs continues after the stimulus is re- 
moved. Every child is familiar with the phenomenon of the 
continuous circle of fire caused by rapidly whirling a glowing 
ember. The retinal process in each part of the eye stimu- 
lated continues to act until the stimulus reaches that part 
again, giving the appearance of a continuous stimulus. A 
convenient way of demonstrating the continuance of sensa- 
tion after the removal of the stimulus is to look steadily at 
the glowing wires of an electric-light bulb and then turn off 
the light, leaving the room dark. The sensation which is 
caused by the illuminated wires will continue for a time and 
may be projected to any part of the room. Blink the eyes 
and it stands out more clearly; close the eyes and the light 



SENSATION 95 

may be seen located within the darkened field. The after- 
effects of stimulation are equally prominent in the cutaneous 
sensations. Touch the back of the hand with the point of a 
pencil and notice the after-sensation when the pencil is re- 
moved. 

These after-sensations are commonly called "after- 
images," which term has been applied mostly to the visual 
sensations. Under some conditions the after-effects of the 
visual stimulus is the opposite of the primary sensation. If 
the after-sensation of the glowing electric-light filaments is 
watched with the eyes closed, it will presently change to an 
intense black projected against the dark field of the closed 
eyes. If the eyes are opened, it may be projected upon a 
white background as a dark image. If, after gazing at a 
bright window from a darkened part of the room, the eyes 
are tightly closed, a picture of the window will be seen in the 
retinal field, but the distribution of light and dark parts will 
be reversed. The sashes will appear light and the panes dark. 
If the eyes are not closed, the image of the window may be 
projected upon any white background. Here, as before, the 
light and shade are reversed. The after-effect of color- 
stimulation is seen in the complementary hue of the primary 
sensation. If, after fixating a yellow cross on a blue back- 
ground for half a minute, one looks at a neutral gray surface, 
the cross will appear in a bluish tone upon a yellowish 
background. Such after-effects have been called '^negative 
after-images,^^ in contradistinction to the after-sensations 
which preserve the same quahties as the primary sensa- 
tions, and which have received the name of ^^ positive after- 
images.^^ 

An interesting effect due to negative after-images may be 
gotten by looking steadily at the dot in the centre of the 
circle in Figure 37 for forty seconds, and then quickly fixating 
the central part of a sheet of white paper. If the after-image 
does not stand out clearly, blink the eyes rapidly several 
times, still fixating the white paper. 




96 PSYCHOLOGY 

Sensory Adaptation. — After a stimulus has acted for some 
time upon a sense-organ the resulting sensation is less fully 
experienced than it was at first. This lessening of the in- 
tensity of sensory impressions, which is due to the continued 
action of the stimulus, is known as sensory adaptation. Sen- 
sory adaptation shows itself most in the sense of smell and 

least in the sense of pain. Odors 
fade out very rapidly if they are 
continuously present to the sense- 
organs. Pain, on the other hand, 
loses very little of its intensity as 
we continue to experience it. All 
the other senses, however, show 
sensory adaptation. The pressure 
of glasses upon the bridge of the 
nose is felt quite distinctly when 
Pjg y they are first put on, but after 

they are worn for a while the 
pressure becomes unnoticeable. A cold bath seems relatively 
less cold after the first plunge. A room which seems very 
brightly illuminated when we first enter it appears less 
bright after the first few minutes. We soon become accus- 
tomed to the sound of the ticking clock and fail to hear it. 
Attempts have been made to explain sensory adap'tation by 
referring it to fatigue in the sense-organs or in the brain cen- 
tres. While fatigue of the nervous tissue will certainly ex- 
plain many cases of sensory adaptation, there may be other 
factors entering into the phenomenon. 

Curiously enough, the term "adaptation" has another 
meaning in psychology. It is used to denote the increase of 
visual sensitivity in faint and bright illumination. On going 
from broad daylight into a darkened room, we are at first 
unable to distinguish objects clearly, but after a few minutes 
our ability to see increases. The eyes become accustomed to 
the faint illumination, or, as we say, they become dark- 
adapted. The same thing takes place when we go from a 



SENSATION 97 

dark room into the broad daylight. At first the light is too 
strong. Not until we become accustomed to it are we able 
to see clearly. In this case the eyes become light-adapted. 
The student will have to determine from the context which 
of the two meanings is intended when the term "adaptation" 
is used. 

Attributes of Sensation. — All sensations possess certain 
essential characteristics. The four most important are: 

1. Quality. 

2. Intensity. 

3. Extensity. 

4. Duration. 

These characteristics do not reveal themselves to observation 
as being essential aspects of sensation in the same degree. 
For instance, it is plain that all sensations possess quality, 
intensity, and duration. But the case is not so clear for 
extensity. Auditory, gustatory, olfactory, and some of the 
organic sensations are thought by some psychologists not to 
have this attribute. It must be admitted that, if it is present 
in these sensations, it plays a more obscure part than the 
other attributes. We shall discuss the matter later. 

Quality. — Quality is the unique and unanalyzable char- 
acteristic which gives sensations their psychic nature and 
marks them off into distinct mental existences. Any ob- 
servable change in quality gives a new sensation. Psycho- 
logically, it is the most fundamental thing in sensory experi- 
ence. The sensation red is qualitatively different from the 
sensation blue. Bitter is different from sweet, pressure from 
pain. We may consider that all sensations of red have the 
same psychic quahty. All groups of sensations which show 
the same intimate sameness of experience may be thought of 
as having the same quality. Taste-sensations exist in four 
different qualities: sweet, sour, salt, and bitter; color-sensa- 
tions also in four: red, yellow, green, and blue, each forming 
a single quality. 

When we consider the whole field of sensations, we find 



98 PSYCHOLOGY 

that it falls apart into larger groups, or modes, and in such 
a way that the differences between the modes is markedly 
greater than the differences between the groups within the 
modes. All the visual sensations make up a single mode, 
the auditory sensations another, the gustatory sensations 
another, and so on. There is a decided break in the quality 
of the sensations when passing from one mode to another, 
as, for instance, when we pass from a sensation of taste to a 
sensation of color. Such a difference we may call a differ- 
ence in modality. On the other hand, within a single mode 
we may pass from one group of sensations to another through 
a gradation of qualitative changes so slight that they escape 
observation, thus making the qualities appear to exist in a 
continuous series. Such a series is illustrated by the tonal 
qualities, where we may go from the lowest bass note to the 
highest treble along a single line of qualitative changes with- 
out a break. The visual sensations form another (although 
much more complex) system of sensation-qualities. The dif- 
ferences within these systems may be called differences of 
quality. 

Although there is as yet no definite physiological evidence 
to settle the matter, we may suppose that the physiological 
basis for the quality of a sensation is to be found in the spe- 
cific kind of nerve-activity aroused in the brain centres by 
the action of a specific kind of sense-organ.^ Differences of 
modality in sensations are based upon the activity of differ- 
ent areas or centres in the cortex of the brain. Thus the 
visual sensations have their seat in the occipital lobes, while 
the auditory sensations have theirs in the temporal lobes. 

Intensity. — Every sensation possesses some degree of in- 
tensity. The same sensation, without changing its quality, 
may vary in intensity from the weakest to the strongest. A 
sound may be soft or loud, a pressure-sensation may be light 
or heavy, and so sensations vary in intensity. We may sup- 
pose that the intensity of sensation depends upon the inten- 
1 See discussion of the "Physiological Basis of Sensations," p. 88. 



SENSATION 99 

sity of the neural activity in the sense-organs and the brain, 
and that the intensity of the neural activity is determined by 
the intensity of the stimulus. There is, then, an indirect rela- 
tion between the intensity of the stimulus and the intensity 
of sensation. Within certain limits, the more intense the 
stimulus the more intense the sensation. The intensity rela- 
tion between the stimulus and sensation may be modified by 
the condition of the sense-organs. If they are fatigued, or 
if adaptation has taken place, a given intensity of the stim- 
ulus will not occasion the same intensity of sensation as it 
would if the sense-organ were not fatigued or if adaptation 
had not taken place. A rose gives a more intense sensation 
of odor when first brought into the room, but after the sense- 
organ has become fatigued the sensation intensity is reduced. 

The minimal and the maximal intensities of sensation 
mark two limiting points in the intensity series of any given 
sensation. The stimulus must reach a certain intensity be- 
fore any sensation is aroused. A very weak stimulus fails 
to produce a sensation. The point at which the stimulus 
becomes strong enough to arouse sensation is called the 
threshold of sensation, or lower limit of sensation} The point 
at which increase in the intensity of the stimulus fails to 
give further increase in the intensity of the sensation is called 
the upper limit of sensation. It should be noted in connection 
with the upper limit of sensation that, when stimuli become 
increasingly intense, other end-organs than those of the 
original sensation are affected. For example, a very loud 
sound, bright light, or intense pressure-stimulus will affect 
the pain-nerves. The presence of the resulting pain-sensa- 
tion is not, however, to be taken as an increase in the inten- 
sity of the original sensation. 

There is no way of measuring directly the intensity of a 
sensation. We can, however, compare like sensations and 

^ It is necessary for the stimulus to act for a certain length of time; a very- 
brief stimulus may fail to arouse sensation, even though it may have an inten- 
sity far above the threshold. 



lOO PSYCHOLOGY 

say, for instance, which of the two is the more intense. In 
fact, we can arrange a number of such sensations in a series 
of intensities from the lowest to the highest. We can then 
measure the different intensities of the stimuK which occa- 
sion the sensations, and so have an indirect measure of the 
intensity of the sensation. We may start with a given stim- 
lus, note the intensity of the sensation which arises from it, 
and then increase the stimulus until we are able to detect a 
"just-noticeable difference" in the intensity of the sensation. 
Continuing the process we obtain a series of sensations which 
are just-noticeably different in intensities, each sensation pos- 
sessing a just-noticeably higher intensity than the one before 
it. Two interesting facts reveal themselves in such experi- 
mental procedure. If, for instance, we compare, by lifting 
successively, weights ranging from loo grams to 105 grams, 
each differing from the other by one gram, we find that we 
are unable to sense the difference between the weight of 100 
grams and those of loi, 102, 103, and 104 grams, respec- 
tively. Not until we reach 105 grams can we note an in- 
crease in the sensation, i. e., increasing the stimulus does not 
bring an increase in the sensation until a certain increment 
to the original stimulus has been reached. This difference 
in the intensities of stimuli required to cause a just-notice- 
able difference in the sensation is called the dijference-threshold. 
The most probable explanation of this fact will be found 
in the -nature of the physiological processes in the sensory 
end-organs and nerves. The nervous mechanism is such that 
a certain inertia of the end-organs must be overcome before 
an added increment to the nervous process can be set up. 
This resistance of the sense-organs to stimuli also explains 
the existence of the threshold, or lower limit, of sensation. A 
rough analogy may be seen in physical inertia. It requires 
more energy to start a piece of machinery than it does to 
keep it going after it is started, and more to change its rate 
of movement than to maintain the changed rate afterward. 
The difference-threshold expresses the increment or decre- 



SENSATION lOI 

ment which must be made to any stimulus before any differ- 
ence in the sensation can be noticed. 

The second fact is that equal increments to the stimuli 
do not produce a change of sensation at different parts of 
the scale of intensities. For example, it requires an increase 
of 5 grams to a loo-gram weight to produce a just-noticeable 
difference in the sensation. But if 5 grams are added to 
200 grams, no difference in the resulting sensation can be 
detected. It requires an increase of 10 grams in this part 
of the intensity scale to cause a noticeable change in the 
sensation, i. e., the difference- threshold varies for different 
parts of the scale. In general we may say that absolute dif- 
ferences in stimuli are more easily detected when the inten- 
sities of the stimuli are weak than when they are strong. 
One ounce added to two ounces makes a noticeable differ- 
ence, but cannot be detected when added to ten pounds. A 
lighted candle brought into a dark room (low light-intensity) 
increases the illumination of the room very noticeably, but 
added to the high illumination of a brightly lighted room 
causes no noticeable difference in the illumination. 

Weber's Law is an attempt to generalize these facts and 
state the relation of the intensity of the stimulus to the inten- 
sity of sensation more exactly. Briefly, it is as follows: 7w 
order to obtain an increase in the intensity of sensation, the 
original stimulus must be increased by a constant fraction of 
itself} If, as has been stated, an increase of 5 grams to the 
stimulus of 100 grams is required to produce a just-noticeable 
increase in the sensation, and an increase of 10 grams for the 
stimulus of 200 grams, then the constant fraction is one- 
twentieth. In order, then, to increase the sensation of any 
weight-stimulus, the weight must be increased by one-twen- 
tieth of itself. The fraction which gives the just-noticeable 
difference of sensation is not the same for all senses. For 
simultaneous light it is one one- hundredth; for sound one- 

^ Fechner's modification of Weber's Law is as follows: Intensity of sensa- 
tion increases as the logarithm of the stimulus. 



I02 PSYCHOLOGY 

fourth. These fractions can be obtained only by long and 
careful experimentation, and different investigators have ob- 
tained different values for the constant fractions. It has 
been found that they vary for different persons and for dif- 
ferent parts of the intensity scale in the same sense. For 
very high and very low intensities Weber's Law does not hold 
at all. It applies only to the middle range of intensity values 
and even there only approximately.^ It has not as yet been 
applied to sensations of temperature and taste. The most 
that can be said for Weber's Law is that it states a general 
fact of experience — the fact that sensation does not increase 
in the same ratio as the stimulus and, further, that in order 
to get an increase in the sensation-intensity, the increment 
to the stimulus must constantly be made greater and greater 
as we pass from the lower to the higher intensities. Or, to 
restate the same fact in another way, it requires a greater 
and greater difference in the intensities of two stimuli to 
produce a just-noticeable difference in the intensity of sensa- 
tions, as we go from the lower to the higher intensities. The 
strict application of Weber's Law involves the assumption 
that all just-noticeable differences in the same class of sensa- 
tions are equal, that the just-noticeable difference in the 
sensations produced by the stimulus of loo grams and 105 
grams is equal to the just-noticeable difference between the 
sensations produced by 200 grams and 210 grams. It would 
further assume that these differences are units of sensation, 
and that the total sensation in each case is made up of these 
units which may be added to, or subtracted from, the sensa- 
tions. These assumptions have never been proved. There 
seems to be no reason for believing that a just-noticeable dif- 
ference in sensations of low intensity is equal to a just- 
noticeable difference between sensations of high intensities. 
Nor can we observe, by the most careful introspection, any 

" For a summary of the results of experimental investigations into the valid- 
ity of Weber's Law, see Ladd and Woodworth: " Physiological Psychology," 
pp. 360-378. 



SENSATION 103 

evidence for the assumed fact that sensations are made up 
of intensity units, nor can we measure a sensation in such a 
way as to be able to say how many units of intensity it con- 
tains. Every sensation is itself, so far as we are able to 
say at the present time, a unit not capable of being broken 
up into smaller units. 

Why it is necessary, in order to get a just-noticeable dif- 
ference in sensation, to make increasingly larger additions to 
the stimulus as its intensity increases, raises a very interest- 
ing theoretical question. Is it due wholly to the nature of 
physiological processes in the end-organs and brain centres? 
Or is it due to purely psychological factors, such as the 
theory of the relativity of consciousness, which holds that 
the nature or value of every conscious state is determined by 
its relation to other conscious states? According to the 
principle of relativity, the intensity of a given sensation 
resulting from an increase in stimulus depends upon the in- 
tensity of sensations already going on, or sensations just pre- 
ceding. We cannot go into these questions at this time 
further than to call attention to these possible interpreta- 
tions of the facts summarized by Weber's Law.^ 

Extensity. — Extensity is to be distinguished from extension. 
Extension is experienced only as the result of combining sim- 
pler experiences (distance, direction, and position) into a 
mental complex. Extensity is an original and native aspect 
of sensation — a kind of "bigness" within which there are no 
parts or divisions which can be distinguished from other 
parts. If first the head and then the point of a pin are 
pressed very lightly upon the forefinger, so that the point of 
the pin does not stimulate the pain-nerves, the two pressure- 
sensations will seem different. The difference is that of ex- 
tensity. The sensations are without any space form, for 
there is no distinguishing of parts, yet they possess different 

^ For a statement of these theories or interpretations of Weber's Law, see 
Ziehen: "Physiological Psychology," pp. 54-61; Ladd and Woodworth: 
"Physiological Psychology," pp. 374-9. 



I04 PSYCHOLOGY 

degrees of native "bigness" or extensity. It is difficult to 
isolate this attribute of sensation, because it is so overlaid 
with the higher and more complex experiences of space per- 
ception. Extensity shows itself to introspection rather as 
the bigness of the sensation than as the size of objects or 
spaces suggested by the sensations. It attaches itself more 
closely to the intrinsic nature of the sensation than do expe- 
riences of extension. The visual sensations, the cutaneous 
sensations, the articular and muscular sensations, all plainly 
have the extensity attribute. On the other hand, sounds, 
tastes, and smells have been denied extensity by some psy- 
chologists, although some, chief among them James, beheve 
that all sensations possess extensity. The roar of a lion is 
bigger than the squeaking of a mouse; the low bass note 
sounds bigger than the high treble note.^ Some smells, like 
the heavy odor of musk, seem more voluminous than the 
lighter ones, such as the odor of camphor; the taste of sweet 
is more voluminous than the taste of sour. Some pains are 
bigger than others. The fine, shooting pain of neuralgia is 
less voluminous than the heavy soreness of a boil, says 
James.2 The extensity differences in the sensations of hear- 
ing, taste, and smell are evidently not so great as they are in 
the sensations of the skin, the muscles, and the eyes. This 
more limited range of experienced difference in the former 
group of sensations may explain the obscure part that ex- 
tensity plays in them. 

The physiological basis for the differences of extensity in 
sensations lies in the differences in the number and outspread 
of nerve- endings. The greater the number of nerve-endings 
stimulated, the greater the degree of extensity in the result- 
ing sensation. In the skin and on the retina of the eye we 
have extended nerve-elements, which are capable of being 
stimulated in different numbers. The stimulation of these 

^ For James's discussion, see his " Principles of Psychology," Vol. II, p. 134; 
" Briefer Course," p. 335. 
^ " Briefer Course." 



SENSATION 105 

nerve-elements gives an attribute of spread-outness which 
varies with the size of the area and number of nerve-elements 
stimulated at any one time. The nerve-endings in the ear 
are not spread out, while those of the tongue and nose are 
normally stimulated in such a way as to give little opportu- 
nity for the experience of extensity differences. 

Duration. — Every sensation begins, rises to its fulness, 
and then wanes. These phases are really not differentiated 
from each other in ordinary experience, yet they furnish the 
basis for a simple experience of duration which is present in 
all sensation. This sensory attribute must be distinguished 
from the duration-of-time perception, which, like extension- 
in-space perception, is the result of the synthesis of different 
sensations. Duration as an attribute of sensation is part 
and parcel of the sensation itself. It must not be confused 
with the perception of how long the sensation lasts. It is the 
sensation content of temporal outspread or temporal bigness, 
a native time quantum. Even the shortest sensation pos- 
sesses this native duration attribute. 

Other Attributes. — Besides the four attributes Just dis- 
cussed, other attributes have been suggested as essential 
characters of sensation. Titchener^ mentions clearness as 
an attribute. Sensations may appear in the foreground or 
in the background of consciousness, in the focus or in the 
margin. Now, since a sensation must appear somewhere 
between these limits, it always possesses some degree of 
clearness. Miinsterberg^ gives the name "vividness" to this 
attribute, and cautions his readers against confusing vivid- 
ness of sensation with intensity. He says: "If the ticking of 
a clock in my room becomes less and less vivid for me the 
more I become absorbed in my work, till it finally disappears, 
it cannot be compared with the experience which results 
when the clock to which I give my full attention is carried 
farther and farther away." A sensation of low intensity 

^ "Text-Book of Psychology," p. 53. 
^ "Psychology and Life," p. 86. 



Io6 PSYCHOLOGY 

may have a high degree of clearness or vividness, while a 
sensation of high intensity may have a low degree of clear- 
ness or vividness. The changes in clearness or vividness 
seem to be due not to sensation alone, but to changes in 
attention. 

There is sufficient evidence to believe that every cutane- 
ous and visual sensation possesses a particular local signifi- 
cance, which is different for every part of the skin and retina 
stimulated. Close your eyes and have some one touch you 
with the point of a pencil, first on the right and then on the 
left hand. You are able to tell without hesitation which 
hand is touched. This means that each sensation, although 
aHke in all other attributes, differs for different regions of the 
skin stimulated. This difference in sensation is a difference 
of local sign. If, however, two points of the skin which lie 
very close together are stimulated, the difference of local 
sign disappears. When the two near points are stimulated 
simultaneously, the two stimuli are felt as one. When the 
distance is sufficiently great, however, the stimuli are dis- 
criminated and felt as two. This is because the difference 
in their local signs is great enough to distinguish one from 
the other. The minimal distance of separation of two stimuli 
which are sensed as two is termed the "two-point threshold." 

This threshold varies for different parts of the skin. It is 
smallest for the tip of the tongue, lips, and fingers, and great- 
est for the regions along the spine. The local-sign difference 
cf sensation is not a difference of space perception, in which 
points are located with reference to each other, and given 
definitely perceived distances and directions between them. 
It is simply a felt difference in sensations coming from differ- 
ent points of the skin surface. It is possible to find regions 
within which the two points of a compass are felt as differ- 
ent, and yet no perception of the distance or direction of the 
points from each other is present. In such cases there is 
merely a local-sign difference in the sensations. The nearer 
the points are together the more the sensations are alike; 



SENSATION 107 

the farther the points are apart the more definite the differ- 
ence in the local sign. 

Visual sensations also possess local significance. Sensa- 
tions which are alike in every respect (in quality, intensity, 
etc.), but which come from different points of the retina, are 
sufficiently unlike to enable us to distinguish the stimuli 
which occasion them. Here, as in the skin, every point of 
each retina gives a sensory character different from the char- 
acter of every other point.^ 

Kinds of Sensations 

Psychological analysis has shown that the old common- 
sense classification of the sensations into the five senses of 
seeing, hearing, tasting, smelling, and feehng (touch) is 
inadequate. There are many more than five senses. The 
sense of "touch," for instance, has been resolved into the 
four distinct senses of pressure, pain, cold, and warmth. 
Each one of these has its own particular kind of nerve-end- 
ings which give, when stimulated, a unique sensory experi- 
ence, different from all others. 

Obviously we shall get different divisions of the sensa- 
tions if we classify them according to the stimuli which occa- 
sion them, or according to the sense-organs to which they 
correspond, or according to the intrinsic quality of the sen- 
sations themselves. A thoroughgoing classification of the 
sensations based upon the different kinds of stimuli which 
occasion them is impossible, because, in many cases, we do 
not know the exact nature of the stimulus which acts upon 
the sense-organ. Such is the case in the sense of smell. 
Without, however, going into the exact character of the 
stimuli, we may divide the sensations into three classes, 

^ Every point in one retina has a corresponding point in the other. Sensa- 
tions from these points have the same local significance. This is demonstrated 
in cases where two stimuli exactly alike, but occupying different positions in 
space, are not distinguished from each other. This is illustrated in stereo- 
scopic vision, where two pictures occupjdng different positions in space are 
seen as a single picture. 



Io8 PSYCHOLOGY 

according as their stimuli are found (i) in the vital organs 
of the body, (2) in the bodily organs of locomotion, or (3) in 
objects external to the body. 

1. Organic Sensations (reporting conditions of the internal 
bodily organs). 

2. Kinassthetic Sensations (reporting movements of the 
body).i 

3. Special Sensations (reporting the character of external 
objects) . 

If we classify the sensations according to their different 
sense-organs, and at the same time subdivide them into 
groups according to their intrinsic qualities, we have the fol- 
lowing classification: 

1. Organic Sensations: 

(a) Sensations from the alimentary canal. 

(b) Sensations from the respiratory organs. 

(c) Sensations from the circulatory system. 

(d) Sensations from the sex-organs. 

2. Kinaesthetic Sensations: 

(a) Muscular, sensations from moving muscles, 

(b) Tendinous, sensations of pull and strain in tendons. 

(c) Articular, sensations of gliding and pressure in 

joints. 

(d) Sensations from vestibule and semicircular canals: 

sensations of position, change of movement and 
dizziness. 

3. Cutaneous Sensations: 

(a) Pressure. 

(b) Pain. 

(c) Cold. 

(d) Warmth. 

' The kinaesthetic sensations are sometimes classified under the organic 
sensations. For instance, Titchener, in Baldwin's " Dictionary of Philosophy 
and Psychology," classifies the organic sensations into: (i) Muscular sensa- 
tions, (2) alimentary sensations, (3) sexual sensations, (4) static sensations, (5) 
respiratory sensations, and (6) circulatory sensations. The muscular and static 
sensations of Titchener's classification are in this text-book placed under the 
kinaesthetic sensations. 



SENSATION 109 

4. Olfactory Sensations: 

(Many sensations, but no characteristic groups of qual- 
ities have been made out.) 

5. Gustatory Sensations* 

(a) Sweet. 

(b) Sour. 

(c) Salt. 

(d) Bitter. 

6. Auditory Sensations: 

(a) Noises. 

(b) Tones. 

7. Visual Sensations: 

(a) Achromatic (brightness). 

White. 

Gray. 

Black. 

(b) Chromatic (color). 

Red. 

Yellow. 

Green, 

Blue. 
The classification here given is not at all satisfactory 
from the psychological point of view, but it is the best that 
can be made at the present time. In the first place, some 
of the subheadings signify elementary sensory experiences 
which cannot be further analyzed, as for instance those of 
pressure, pain, warmth, and cold; while others, like those 
under Organic and Kiuccsthetic Sensations, signify highly 
complex experiences, i. e., are made up of simpler sensations. 
The so-called sensations of hunger, thirst, and nausea from 
the alimentary canal, the sensations from the sex-organs, the 
muscular, tendinous, and articular sensations may not present 
any distinct sensory qualities at all, but may be nothing 
more than certain combinations and blends of pressure, pain, 
and temperature sensations. Or, at least, they may be prim- 
itive and undifferentiated forms of these sensations. 



CHAPTER V 

ORGANIC, KINESTHETIC, AND CUTANEOUS 
SENSATIONS 

Organic Sensations 

The organic sensations include a great mass of undiffer- 
entiated and vague sensory experiences that are located in 
and about the vital organs. From the visceral or abdominal 
region come dull internal pains of varying intensities, vague 
sensations of fulness, tension, and pressure. From the upper 
part of the alimentary canal we get the more definite experi- 
ences of hunger, thirst, and nausea. Hunger is located in 
the stomach as a dull, gnawing pain or ache. Thirst is felt 
quite definitely in the back part of the mouth, and in the 
throat as an insistent pressure combined with a sense of 
roughness and dryness. Nausea is felt in the oesophagus 
and stomach, and is difficult to analyze into its constituent 
elements of sensation. In the thoracic region we sometimes 
experience a sense of a want of air, stuffiness, or, even more 
intensely, suffocation, due to the physiological condition of 
the lungs when shut off from an adequate air-supply. The 
sensations coming from the acts of respiration arise from the 
intercostal muscles and diaphragm, and should be classed 
among the kinaesthetic sensations. While, ordinarily, we do 
not sense the condition of the heart, yet in fright, anger, and 
other emotions, and also during and after extreme physical 
exertion, sensations arise in the cardiac region. In fright 
there is a sinking sensation, caused probably by the sudden 
change in the heart's action. In anger and heavy physical 
exertion there appears a vague, rhythmic tension about the 
heart. The ''heart jumping up in the mouth" probably 



ORGANIC SENSATIONS III 

comes from the sensations of muscular contraction in the 
pharynx. The sex-organs add another group of sensations 
to the organic experiences. The organic experiences, so far 
mentioned, are without doubt highly complex products, com- 
pounded out of simpler sensations. If analysis were not so 
difficult here, we should probably be able to resolve these 
experiences into sensations very much akin to those of pres- 
sure, pain, cold, and warmth of the cutaneous sensations. 
The stimuli which set up these organic experiences consist 
in the physiological condition of the organs themselves, which 
affects the sensory nerve-endings, and thus gives rise to the 
experience. In cases where vital organs are not supplied 
with sensory nerves, any serious disturbance in such organs 
is experienced as pain in neighboring sensitive tissue. 

It is interesting to note that some of the ancient writers 
located the feelings and emotions in the vital organs, and 
modern investigators have pointed out more definitely the 
close connection between the vague and unanalyzable organic 
sensations on the one hand and the feelings and emotions on 
the other. The condition of the vital processes has much 
to do in determining the nature of the emotional tone. In- 
digestion will predispose one to a pessimistic and gloomy 
point of view, while a healthy digestion tends to cheerful- 
ness. Ordinary speech has several expressions which recog- 
nize the idea that the emotions are based upon organic con- 
ditions and disturbances: "The bowels of compassion," "the 
complacency of a full stomach," "the bile of one's wrath," 
"the emotions of the heart," "his heart is in his work," etc. 
Even among psychologists the theory has been entertained 
that the feelings are unclear and undifferentiated organic 
sensations^ — diffuse organic experiences that arise from the 
stimulation of unspecialized nerve-endings, and therefore do 
not stand out clearly in consciousness with definite sensory 
qualities as do the other groups of sensations. It is certainly 
true that many of the organic sensations are obscure, very 

^Titchener: "A Text-Book of Psychology," § 74. 



112 PSYCHOLOGY 

vaguely located, refer to the organism as a whole rather than 
to any definitely distinguishable part of it, and consequently 
appear as subjective modifications or attitudes. On the 
other hand, the special sensations refer to the characteristics 
of objects that appear to exist independently of our conscious- 
ness. Many of the organic sensations are altogether unpro- 
jected, i. e., have no reference beyond themselves, suggest 
nothing over and above the subjective experience itself. 
All these characteristics make the more obscure organic sen- 
sations strikingly similar to our feeling or affective experi- 
ences. However this may be, the organic sensations furnish 
a continuous and constant accompaniment or background of 
all mental experiences. We are never free in normal waking 
life from this undertone of inner bodily experiences. 

KiN-^STHETic Sensations 

Muscle, Tendon, and Joint Sensations. — The muscles, 
tendons, and articular surfaces are supplied with sensory 
nerve-endings which give, when stimulated, sensations of 
movement. These sensations, together with the sensations 
that arise from the vestibule and semicircular canals of the 
inner ear, are known as kincBsthetic sensations. 

The sensory end-organs consist of muscle-spindles and 
tendon-spindles in which fine branchings of nerve-filaments lie 
next to or coil about the muscle and tendon fibres within 
the spindles. Other nerve-endings — Pacinian corpuscles and 
end-bulbs — -are found in the muscles, tendons, joints, and 
periosteum. It is probable that they, too, have to do with 
the sensations of movement. 

The stimuli which excite these nerve-endings are the 
contraction and relaxation of the muscles, the pull and ten- 
sion of the tendons, and the gliding of the tendons over the 
joints, and possibly the pressure of the joint surfaces against 
each other. 

The muscle, tendon, and joint sensations are blended with 
the cutaneous sensation of pressure whenever we move any 



KINESTHETIC SENSATIONS 



113 



part of the body. The cutaneous sense is stimulated when 
the body changes its position by the folding, stretching, or 
pulling of the skin. In order to study the kinaesthetic sensa- 




FiG. 38. — Tendon with nerve-plaque made up of the endings of sensory fibres 

seen entering from above, rfnc, arborization of the sensory fibres. 

(From Ladd and Woodworth, after Ciaccio.) 

tions alone, we must find some way of isolating them from 
the skin sensations. This may be done by making the cuta- 
neous tissue anaesthetic by the use of cocaine or ether spray. 




Fig. 39. — Nerve-plaque in a muscle-spindle. The nerve-fibre entering at the 

left subdivides to form the network shown. 

(From Thorndike's "Elements of Psychology," after Barker.) 



It is almost impossible to separate the muscle, tendon, and 
joint sensations from each other, for the reason that most 
movements awaken all three at once. But those who have 



114 PSYCHOLOGY 

had practice in introspection may be able at times to pick 
out these different sensory experiences from each other. By 
gripping the hand tightly, one gets a dull internal pressure- 
like sensation in the muscles of the forearm. Practically the 
same sensation may be obtained by pressing upon the mus- 
cles of the arm with the hand. The sensation will stand out 
more clearly if the skin surface has been previously made 
anaesthetic. 

The tendon sensation appears when one lifts a heavy 
weight by pulling directly upward with the arm and allowing 
the weight to hang perpendicularly from the shoulder. While 
the sensation in question is qualitatively different from the 
muscle sensation aroused at the same time, we are unable 
to describe it further than to say that it is a sensation of 
pull or strain in the wrist and elbow joints. 

The joint or articular sensations are not so clearly made 
out as the muscle and tendon sensations. But if the left 
forefinger is grasped firmly between the thumb and the first 
two fingers of the right hand and pressed inward while the 
finger is bent back and forth at the middle joint, a smooth, 
ghding sensation will be experienced which seems very much 
like a light internal pressure. One must disregard the cuta- 
neous pressure caused by grasping the finger by the other 
hand. 

As a proof that these sensations really play the chief part 
in our perceptions of movements and positions of the limbs, 
we may point out the fact that complete anaesthesia of the 
skin surface does not interfere materially with the ability to 
perceive the position and movement of any member of the 
body, while anaesthesia of the joints or of the muscles and 
tendons seriously interferes with such perception and reduces 
the power of making co-ordinated movements. 

We shall see later, when we take up the combination of 
sensations into space perceptions, that a large part of the 
raw material out of which these perception complexes are 
formed is drawn from the kinaesthetic sensations. We de- 



KINESTHETIC SENSATIONS II5 

pend very largely upon these sensations for the conscious 
material out of which we construct our space world. Not 
only the sensations which arise in the larger muscles and 
their adjacent joints and tendons, but the finer muscles con- 
trolHng convergence, divergence, and accommodation in the 
eyes furnish conscious elements which are combined with the 
tactual and visual sensations into definite space perceptions. 

It is important that the student should bear in mind 
from the beginning that these sensations — in fact, all sensa- 
tions — are only the psychological elements out of which the 
complexes of perception and other higher mental processes 
are built up. These sensations must be thought of only as 
simple qualities of consciousness, and never as the more 
highly developed perceptions of weight, definite perceptions 
of position, direction, or distance. These latter experiences 
are complexes of sensations which we gain through experi- 
ence by associating and combining the elementary sensations 
in various ways.^ 

Sensations from Vestibule and Semicircular Canals. — ^A 
set of rather obscure and unobtrusive sensations arises in 
the vestibule and semicircular canals of the ear. With slight 
stimulation of these organs, it requires very careful introspec- 
tion to detect their presence in consciousness. They appear 
as swimming sensations in the head, dizziness, sensations 
coming from the position and sudden change of the move- 
ment of the head, or the body as a whole. They play an 
important part in maintaining the position and equilibrium 
of the body. The movements which restore disturbed equi- 
librium are known as "compensatory movements." They 
are present in nearly all animals. If, for instance, the body 
is forced from its upright position, when such a position is 
advantageous or desired, immediately the compensatory re- 
flexes throw the head and body back to their normal posi- 
tions. In cases of extirpation of the vestibule and semi- 
circular canals in animals the sense of equilibrium is lacking, 

1 See Titchener: " A Text-Book of Psychology," §48 and §50. 



Il6 PSYCHOLOGY 

as is shown by the loss of compensatory movements, dis- 
turbed locomotion, running in a circle, unusual positions of 
the head, etc. Deaf-mutes, whose internal ear, including the 
vestibule and canals, is destroyed, do not experience the sen- 
sations of swimming in the head, or dizziness when rotated 
in a revolving chair, or when whirling on the heel.^ These 
facts point to the vestibule and semicircular canals as con- 
taining the sense-organs for the sensations under discussion. 
The vestibule and semicircular canals form the upper part 
of the internal ear, the lower part of which is the cochlea, 
the true sense-organ of hearing. 

On the inner walls of the membranous semicircular 
canals, and within the utricle and saccule of the vestibule, 
are tufts of hair-like cells projecting into the endolymph, a 
fluid which fills the canals. The hair-like cells in the utricle 
and saccule support a number of crystal-like formations, or 
otoHths, which are held in place by a gelatinous substance. 
About the base of these hair-cells and those in the semi- 
circular canals are distributed the nerve-endings of the ves- 
tibular nerve, whose fibres connect with the cerebellum. 

The stimulus which acts upon the hair-cells consists in 
the varying pressure of the endolymph, which bends them 
whenever any change of position or movement of the head 
takes place. The canals of the ear lie in different pknes, one 
horizontal and two vertical, at right angles to each other. 
The position of the canals is such that any movement of the 
head will cause the endolymph to act upon the hair-cells in 
one or more pairs of canals. Head movements will cause a 
lag or back-flow of endolymph in the canals, thus bending the 
hair-cells in an opposite direction to the movement and so 
exciting the nerve-fibres. Therefore, turning rapidly upon 
the heel will cause swimming sensations in the head in the 
direction of the movement. The sensation will continue 

^ Deaf-mutes depend upon visual sensations for sensory cues to position 
and equilibrium. When their eyes are closed or blindfolded, they show a 
decided disturbance of the sense of position and equilibrium. 



KINiESTHETiC SENSATIONS II7 

until the fluid in the canals affected takes up the motion of 
the head. Then they will cease. If movement is suddenly 
arrested, and we stand still after whirling upon the heel, we 
experience the swimming sensations in the direction opposite 
to the original movement, because when we stop the endo- 
lymph continues, for a time, its movement forward, and so 
bends the hair-cells in the direction of the original move- 
ments and reverses the sensation. The direction of the 
swimming sensation may be changed from the horizontal to 
the vertical plane by inclining the head on the shoulder dur- 
ing rotation, and then raising it to an upright position when 
the rotation is stopped. We then get the swimming sensa- 
tions in the vertical directions. Under these conditions, 
when the head is bent down upon the shoulder the vertical 
canals are brought more nearly into the plane of rotation, 
and consequently the endolymph in these canals is affected 
more by the movement of rotation than in the others, with 
the result that the sensations correspond in direction to the 
plane of the canals. 

With a little practice the student may learn to observe 
the swimming sensations during and just after sudden move- 
ments of the head in any direction. The more intense of 
these sensations are commonly known as sensations of diz- 
ziness, or rotation. 

The hair-cells in the utricle and saccule are weighted with 
otoliths, which make them still more sensitive to the differ- 
ent positions of the head. These otoliths drag down upon 
the hair-cells, pulling in the opposite direction to any change 
of position. By exerting varying tensions in different direc- 
tions, according to the position of the head and body, vague 
pressure-sensations are set up which serve as indices of posi- 
tion, equilibrium, and locomotion.^ 

^ For a more complete treatment of the sensations of the vestibule and 
semicircular canals, see Ladd and Woodworth: " Elements of Physiological 
Psychology," §34, §35, and §36, pp. 208-212. Titchener: "A Text-Book of 
Psychology," §§5i-5S, PP- 173-182. 



ii8 



PSYCHOLOGY 




Cutaneous Sensations 

An object placed against the skin surface arouses a num- 
ber of sensations, all at the same time : sensations of pressure, 
warmth and cold, and, in some cases, pain. 
Although by careful observation we can 
readily distinguish the different qualities of 
these sensations from each other, we usually 
think of the combined effect of all these sen- 
sations of the skin as the "sense of touch." 
The experiences which we get from this so- 
called "sense of touch" are not simple ex- 
periences. Hard 
and soft, smooth 
and rough, wet and 
dry, sharp and 
blunt, round and 
cubical, are the re- 
sult not of a single 
sense, but of com- 
bining different cu- 
taneous sensations. 
Even the muscular 
and articular sensations may be 
part of these complex experiences.^ 
The experiences which we get 
from the skin as a whole need to 
be analyzed into their elements, 
and so, in the following sections, 
we shall treat of each cutaneous 
sense alone. 

The End-Organs. — The cutane- 
ous sense areas consist of the skin, lip surfaces, lining mem- 
brane of the mouth and throat cavity, conjunctiva and 

1 See Titchener: "Text-Book of Psychology," p. 171, §50, and Ladd and 
Woodworth: " Physiological Psychology," p. 347, §26. 



Fig. 40. — Dia- 
gram showing 
the nerve-end- 
ings in skin. 
(Retzius.) 

(Taken from Quain's 
"Elements of 
Anatomy.") 




Fig. 41. — Corpuscle of Meiss- 

ner: n, sensory fibre; a, 

its branching termination 

within the corpuscle. 

(From Ladd and Woodworth, after 
Ranvier.) 



CUTANEOUS SENSATIONS II 9 

cornea of the eye. In these areas and in the tissue imme- 
diately underneath are several kinds of nerve-endings, show- 
ing various terminal formations. 

About the roots of the hairs which are found on a large 
part of the skin surface are coiled the terminal branches of 
sensory nerves. These are stimulated by touching the hairs, 
or the skin on the '^ windward" side of the hairs. In the 
papillae or among the epithelial cells of the palms, soles, and 
lip surfaces, where hairs are not present, are a large num- 




FlG. 42. — Plume-organs of Ruffini with the sensory fibre's arborization. 
(From Thorndike's "Elements of Psychology," after Barker.) 

ber of tactile nerve-endings, called "Meissner's corpuscles." 
Each corpuscle consists of a small, oval body, about which 
nerve-fibres intertwine and then, entering the interior of the 
corpuscle, end in small enlargements. To the nerve-endings 
about the hair-roots and the corpuscles of Meissner is as- 
cribed the sense of pressure. 

The simplest form of end-organ is that of the ^^Jree nerve- 
endings,'" consisting of nerve-fibres which have lost their 
medullated sheath and lie between the epithelial cells of the 
epidermis. They have been found, also, in the cornea of 
the eye, where the sensation of pain is very prominent. The 
free nerve-endings are the end-organs for pain. 

In the deeper layers of the skin are found cylindrically 
shaped bodies with very finely divided nerve-fibrils, forming 
a small plume-like structure. They are known as the ^' plume- 



I20 



PSYCHOLOGY 




organs of Ruffini,^' and to them is attributed the sense of 
warmth. 

From the fact that the "end-knob of Krause'' (consisting 
of a small spherical body of granular matter, into which 
unmedullated nerve-fibres pass and end in 
a coiled mass), is found in the conjunctiva 
of the eye, which possesses sensitivity to 
cold, but not tactile sensation, and in the 
mucous membrane of the mouth, which 
is especially sensitive to cold, it is argued 
that the "end-knob of Krause" is the sen- 
sory end-organ for cold. 

The ''Pacinian Corpuscles" found in 
the subcutaneous tissue may possibly 
serve as the sense-organs for heavy pres- 
sure, as distinguished from the lighter pres- 
sure of the skin. 

The suggested correlation of the dif- 
ferent cutaneous sensations to definite 
nerve-endings cannot be taken as final. 
The evidence at best is only indirect. 
Even where the evidence seems convinc- 
ing, there are some perplexing facts. For 
instance, the ''tactile corpuscles" are very 
numerous in just those parts of the skin which are most sen- 
sitive to pressure, and very few or practically absent from 
parts of the skin where this sense is dull. This seems to be 
good evidence for assuming that the "tactile corpuscles" 
are the sense-organs for pressure. But it has been proved 
that some parts of the skin that possess sensitivity to pres- 
sure are lacking in this particular kind of end-organ. Of 
course, it may be that some of the senses have more than 
one form of nerve-ending. 

The Brain Centres. — The cortical centres for the cuta- 
neous sensations are in the region along the fissure of Ro- 
lando, in the so-called somaesthetic area. This area consti- 



Fig. 43. — End-knob 
of Krause: n, 
sensory fibre; t, its 
branching termi- 
nation within c, 
the capsule. 

(From Ladd and Wood- 
worth, after Dogiel.) 



CUTANEOUS SENSATIONS 121 

tutes the brain centre for the "muscle- sense," as well as the 
centre for the cutaneous sense. (See Figure 28.) The exact 
boundary of the somassthetic area is not yet made out clearly. 
Most physiologists place it in the region just posterior to the 
fissure of Rolando, opposite and corresponding to the motor 
centres which lie on the anterior side of the fissure. Within 
the somaesthetic area the skin of the feet and legs is repre- 
sented by the upper part of the area, the skin of the trunk 
and arms by the middle part, while the head is represented 
by the lowest part. So that, with respect to the cutaneous 
sensations, a man may be said to stand on his head in his 
brain. A lesion in this region, on one side of the brain, is 
attended by a loss of all the cutaneous sensations (except 
pain) on the opposite side of the body. The centre for pain 
has not been located. 

Pressure-Sensations. — If an object is pressed upon the 
skin surface lightly, the resulting sensation of pressure is 
different in quality from the sensation aroused by a more 
intense pressure contact. The latter sensation has a dull, 
heavy quality, akin to a slight ache. It appears to come 
from the underlying muscles and is probably the result of 
excitation of sensory nerves among the muscle-bundles. We 
shall, accordingly, distinguish between ^^ light pressure" and 
"heavy pressure." 

If any portion of the skin surface (say a half-inch square 
on the volar side of the forearm) is completely explored with 
the end of a soft bristle (a horsehair 2 cm. long) that will 
bend easily and will, therefore, not exert too strong a pres- 
sure, it will be found that certain parts of the area do not 
respond with any sensation at all. But certain other parts, 
''pressure spots," will respond with a clear-cut sensation of 
pressure. These pressure spots appear to be permanently 
located. They are distributed in an irregular manner and 
vary very much for different parts of the skin. They are 
most plentiful in the finger-tips, where the corpuscles of 
Meissner are found in large numbers. On the hairy parts 



122 PSYCHOLOGY 

of the skin a pressure spot is usually found on the windward 
side of each hair, just over the hair-root, or follicle. They 
are also found on the surfaces between the hairs. They 
react when the skin is pulled or stretched, as well as when 
pressure is applied. This punctiform character of the pres- 
sure surfaces is shared by all the other cutaneous senses. 
Within the same area we shall find pain spots, cold spots, and 
warm spots. The warm spots are fewest in number, while 
the pain spots are most numerous; the pressure and cold 
spots are equally numerous on most skin areas. 

It must be remembered that the pressure spots can be 
discovered only by light pressure. If the pressure upon any 
point of the skin is increased the skin is indented, causing 
neighboring sensitive areas to react so that any point of the 
skin is sensitive to ordinary pressures. This explains why 
pressure appears to be continuous. Pressure-sensation arises 
not only from pressure applied to the skin surface, but from 
the muscle-bundles and from the joint surfaces, when they 
are pressed together. This we may call "heavy pressure." 

The acuity or delicacy of pressure-sensations, as measured 
by the lightest pressure-stimulus that will cause a just-notice- 
able sensation, varies for the different parts of the skin. It 
is most acute for the tips of nose, tongue, lips, finger-tips, and 
forehead, and bluntest for the loins, the shins, and the soles. 
It requires from twelve to sixteen times more pressure to 
excite a minimal sensation on the latter surfaces than it does 
on the former. 

The "two-point threshold," or just-noticeable local dif- 
ference, also varies for the different parts of the skin. On 
the tip of the tongue the points of a compass may be sensed 
as two when they are i mm. apart; on the finger-tip, 2 mm.; 
on the outer surface of the lips, 5 mm.; the inner surface, 
20 mm.; on the back of the hand, 30 mm.; along the spine, 
54 mm. 

Pain-Sensation. — As in pressure, so in pain sensations, we 
can distinguish between the cutaneous pain-sensations and 



' " CUTANEOUS SENSATIONS 1 23 

the dull subcutaneous ache. Pain is very widely distrib- 
uted, coming from nearly all parts of the body. There are 
some exceptions. Certain portions of the visceral and other 
vital organs are devoid of all sensation. A small area on the 
inner side of each cheek is insensitive to pain-stimuli. On 
the other hand, the cornea of the eye seems to possess only 
pain-sensations, or at least the threshold of pain is so low- 
that no other sensations can break through the sensory ex- 
perience of pain when the cornea is stimulated. From the 
fact that pain-sense is so widely distributed in practically 
all parts of the body, it has generally been regarded as a 
"common sensation," with no specific end-organs. It is 
now thought, however, that cutaneous pain arises from the 
stimulation of the "free nerve-endings." 

The pain spots are very numerous in all parts of the skin. 
If, with the point of a fine needle or a stiff-pointed bristle, 
we explore a small area on the back of the hand, which has 
been previously explored for pressure spots, we shall find 
that the pain spots outnumber the pressure spots very greatly. 
There may be over one hundred pain spots to the square 
centimetre in some parts of the skin. The most sensitive 
of these pain spots may be located very readily. Care 
should be taken to put the point of the needle down gently, 
and always with the same intensity. 

Impulses set up by pain-stimulation require a longer 
time to reach the cortical centres than those from pressure- 
stimulation. Or, at least, the latent period, or the period of 
retardation of pain-sensations, is longer than in that of pres- 
sure-sensations. Strike the back of the hand smartly with 
a lead-pencil. Notice that the sensation of pressure appears 
first, then an instant later the sensation of pain. This sug- 
gests that the nerve-impulses from the pressure and pain 
end-organs are conducted to the brain centres along different 
paths. There is pathological evidence to support such a 
theory. 

The after-images of pain remain longer than those of 



1 24 PSYCHOLOGY 

pressure, and there is much less adaptation in pain than in 
pressure. We do not "get used" to pain-sensations as we 
do to pressure. The higher intensities of pain are much 
more insistent than other sensations. They command atten- 
tion and crowd out the other contents of consciousness. 

The sensation of pain should not be confused with the 
feeling of unpleasantness which, in common speech, is often 
designated by the terms "pain" and "painful." This con- 
fusion arises from the fact that nearly all pain-sensations 
are unpleasant. While it is exceedingly unpleasant to lose 
one's purse, there is necessarily no pain- sensation involved 
in the experience, although we commonly speak of it as 
"painful." But pain as a sensation and pain as a feeling 
are entirely different experiences. We shall refer to this dis- 
tinction again when we discuss the feehngs. 

Sensations of Cold and Warmth. — The sensations of cold 
and warmth are often erroneously thought of as different 
degrees of a single sense. They are, really, distinct sensa- 
tions of entirely different qualities, and they arise from the 
stimulation of separate nerve-endings. The tendency to 
think that they belong to the same sense is probably aided 
by the fact that temperature, as a physical condition, is a 
single, unbroken continuum. The further fact that the sen- 
sation of cold seems to pass gradually into the sensation of 
warmth through a point of indifference, or zero, augments the 
tendency to think of them as different degrees of the same 
kind of sensation. 

Both cold and warmth sensations appear on the skin 
surfaces in the same punctiform manner as do pressure- 
sensations. The warm spots are somewhat less numerous 
than the cold spots, while the cold and pressure spots are 
about the same in number for any given area. If a blunt- 
pointed stylus of metal, having a temperature of 15 degrees C. 
(59 degrees F.) is drawn lightly across the inner surface of 
the forearm, in addition to the pressure-sensation sudden 
flashes of cold will appear. (The point of a lead-pencil will 



CUTANEOUS SENSATIONS 1 25 

stimulate some of the more sensitive cold spots.) The spots 
where these cold sensations appear are arranged in irregular 
groups and chains. Sometimes isolated spots may be found. 
A curious fact is met with when the stylus is heated to 45 
degrees C. (113 degrees F.), or above, and placed upon a cold 
spot. The spot will respond with a perfectly definite sensa- 
tion of cold. This is called the "paradoxical sensation of 
cold." 

When the stylus is heated to from 37 degrees C. to 40 de- 
grees C. (99 to 104 degrees F.) the warm spots may be lo- 
cated. The sensations of warm seem more diffuse and are 
located with more difficulty than cold-sensations. They also 
come to full intensity more slowly than the cold-sensations, 
which appear very promptly when the stim.ulus is apphed. 
When the stylus is heated to 50 degrees C. (122 degrees F.) 
the pain spots respond with the sensation of pain. 

The so-called "hot sensation" is a combination of warm 
and cold sensations, while "burning hot" is a combination 
of warm, cold, and pain. "Biting cold" is a combination 
of cold and pain. These complex sensory experiences are 
aroused when surfaces of extreme temperatures (above 45 
degrees C, or 113 degrees F.; or below 12 degrees C, or 53 
degrees F.) are applied to the skin. It is a common obser- 
vation of every-day life that, under certain circumstances, 
we often momentarily confuse very hot and very cold. A 
very hot water-pipe may be sensed at the first instant that 
the hand comes in contact with it as icy cold. The follow- 
ing diagram will show the relations of cold, warm, and pain 
sensations to each other. 

Temperatures of from 30 degrees C. to 36 degrees C, 
being near the physiological zero, appear to the skin indiffer- 
ent or neutral. If the temperature is lowered the stages of 
cool, cold, and biting cold are successively passed through. 
At 12 degrees C. the sensation of pain appears, and rises 
very rapidly with further decrease of temperature. If the 
temperature is gradually raised from physiological zero, the 



126 



PSYCHOLOGY 



stages of lukewarm, hot, and burning hot are experienced. 
At 45 degrees C. cold (paradoxical cold) is added to the 
warm sensations and continues for the temperatures above. 
At 50 degrees C. pain is added to the complex and gives the 






10 


20 


30 


40 


■*?50 










g 




&> 








g 


.5 


-S 




-8 




■a 


■♦* J. 


5§ 




a 


a 


.^ 


i2 s 



Fig. 44. — Diagram showing the relations of cold, warm, and pain sensations 
to each other. The figures on the base line indicate the temperature in 
centigrade. 

(From Pillsbury's " Essentials of Psychology," after von Frey.) 



experience of burning hot. Only between 36 degrees C. and 
45 degrees C. is the warm sensation unmixed. Likewise, only 
between 30 degrees C. and 12 degrees C. are the cold 
sensations unmixed. 

Sensations of cold and warmth may be aroused by organic 
processes within the body. In fever and chills, temperature- 
sensations are set up by pathological organic disturbances. 
They may also be aroused in emotional experiences, as in 



CUTANEOUS SENSATIONS 1 27 

fear, shame, etc. The application of certain substances, like 
mustard, pepper, menthol, and alcohol to the skin gives sen- 
sations of temperature. 

Adaptation of the temperature end-organs to cold and 
warm stimulation is very marked. We easily adapt our- 
selves to varying degrees of temperature. Different parts 
of the bodily surface are constantly subjected to different 
temperatures, as, for instance, the tongue and the forehead, 
yet the experiences of temf>erature arising from them are 
not different. A room that seems warm when we first enter 
will shortly become indifferent if we remain. Likewise a 
room that seems cold at first appears warmer as we become 
accustomed to it. It seems that any portion of the skin 
may, within certain limits, become temporarily adapted to 
different temperatures so that they appear indifferent. Fill 
three bowls with water of different temperatures, one at 20 
degrees C. (68 degrees F.), one at 30 degrees C. (86 degrees 
F.), and the remaining one at 40 degrees C. (104 degrees F.). 
The water at 30 degrees will feel indifferent, neither warm 
nor cold. Place one hand in the water at 20 degrees C. and 
the other hand in the water at 40 degrees C. Leave them 
there two minutes, then plunge both hands in the water at 
30 degrees C. This will feel decidedly warm to one hand 
and cold to the other. To explain this fact, viz., that the 
same absolute degree of temperature in the stimulus may 
sometimes cause the sensation of cold and sometimes the 
sensation of warm, we may suppose that the physiological 
zero, or indifference-point of the skin, has been raised in one 
case and lowered in the other, and that any temperature 
above the physiological zero will arouse sensations of warm, 
while any temperature below the physiological zero will 
arouse the sensations of cold. 

Recent physiological investigations of the effect of sever- 
ing certain, sensory nerves supplying a given area of the 
skin upon the cutaneous sensations of that area show con- 
clusively that the sensory nerves which carry impulses from 



128 PSYCHOLOGY 

the subcutaneous tissues are separate from the sensory 
nerves supplying the skin surface.^ In these investigations 
the radial and external nerves of the left arm were cut, and 
then the part of the cutaneous area from which these nerves 
lead was subjected to rigid experimentation. The most con- 
clusive result was that, while practically all the superficial 
cutaneous sensations were lost, the subcutaneous sensations 
of heavy pressure and pain (dull ache) and kinaesthetic sen- 
sations were not destroyed by the operation. There re- 
mained crude localization of heavy pressure, but no dis- 
crimination of two points or the shape of objects. This in- 
dicates that the nerve-fibres for these senses run with the 
deeper-lying motor nerves. The psychological implication 
points to the complete separation of the subcutaneous and 
cutaneous senses. 

Careful exploration of the cutaneous surface during the 
process of recovery or reuniting of the severed nerves showed 
that there are two systems of cutaneous senses. During the 
first stage of recovery cutaneous pain and temperature sen- 
sations from extremes of heat and cold (above 45 degrees C, 
or 113 degrees F.; and below 20 degrees C, or 68 degrees F.) 
returned. There was, however, during this stage no sensi- 
bility to light pressure, or to moderate degrees of tempera- 
ture between 25 degrees C. (77 degrees F.) and 40 degrees C. 
(104 degrees F.), i. e., no warm and cold sensations of low 
intensities could be aroused, although the higher intensities 
of cold and warm were present. In this stage of recovery 
only the more intense stimuli aroused sensations. This sys- 
tem of sensory experiences was given the name of protopathic 
sensations. Some months later, as recovery proceeded, an- 
other set of sensations appeared: light touch and moderate 
degrees of cold and warm sensations of temperatures rang- 
ing from 25 degrees C. to 40 degrees C. Accurate cutaneous 
localization and ability to recognize two points and the shape 

^ Rivers and Head: "A Human Experiment in Nerve Division," in Brain, 
1908, vol. XXXI, p. 323. 



CUTANEOUS SENSATIONS 1 29 

of objects reappeared with this group of sensations. These 
were called the epicritic sensations. The protopathic warm 
and cold were punctiform, while the epicritic were non- 
punctiform. The protopathic sensations responded only to 
strong intensities of stimulation, while the epicritic responded 
only to light stimulation. It was therefore concluded that 
the protopathic senses were more rudimentary and not so 
highly developed as the epicritic. While this investigation 
adds much to our knowledge of the cutaneous sensations, it 
is doubtful whether it proves the existence of two distinct 
forms. Franz^ has shown that the transition from the pro- 
topathic to the epicritic sensibilities is gradual. It may well 
be that the so-called epicritic sensations are simply refine- 
ments of the cutaneous sensations. 

Certain pathological conditions in the nerve-pathways of 
the spinal cord and nerve-root furnish interesting dissocia- 
tions of the cutaneous sensations. In some diseases the sen- 
sation of pressure from more or less definite parts of the 
skin surface is lost, while sensations of pain and temperature 
remain. In others all sensations of temperature and cuta- 
neous pain are destroyed on extended areas, leaving the 
sensation of cutaneous pressure intact. 

^Journal of Comparative Neurology and Psychology, igog, vol. XIV, pp. 
107, 215. 



CHAPTER VI 
OLFACTORY AND GUSTATORY SENSATIONS 

Olfactory Sensations 

End-Organ. — The sensitive area, regio olfactoria, for the 
sense of smell is located in the upper part of the nasal cavity, 
somewhat removed from the air-currents of ordinary breath- 
ing. Only by sniffing can the full force of the olfactory 
stimuli be brought to the sensory nerve-endings. The regio 
olfactoria is hardly as large as the surface of a dime (250 sq. 
mm. in each nasal chamber). In this area are found the 
sensitive olfactory cells, lying between supporting epithelial 
cells and bearing tufts of from six to eight cilia upon their 
peripheral ends. These cells are true nerve-cells, upon which 
the stimulus acts directly. They extend to the surface of 
the limiting membrane through which the cilia pass in order 
to be exposed to the olfactory stimuli. Any abnormal con- 
dition of the mucous membrane will disturb the proper func- 
tioning of these sensitive cells. A severe cold in the head 
will be accompanied by almost complete loss of the sense 
of smell. Catarrhal conditions of the nasal passages will 
impair the sensitivity of this sense. 

The fibres from the sensitive olfactory cells connect with 
other neurones which pass to the olfactory lobes, the lower 
brain centre, which in turn sends fibres to the gyrus uncinatus 
of the hippocampal lobes, which constitute the cortical or 
higher centre for the olfactory sense. 

The Stimulus. — It is a curious fact that we do not know 
definitely what the stimulus is which excites the olfactory 
cells and arouses the sensations of odor. It is very probable 

130 



OLFACTORY AND GUSTATORY SENSATIONS 



131 




that odoriferous substances reach the end-organs in gaseous 
form. Substances that give out odor must therefore emit 
small gaseous particles which reach the olfactory region and 
there set up chemical reactions, which differ in character 
with the different substances. The variation in the chemical 
reactions would then (so far as the stimulus is concerned) 
account for the differences in 
olfactory sensations. This 
theory does not help us very 
much, for the different chemi- 
cal reactions set up on the 
mucous membrane of the nasal 
surfaces have not yet been 
determined. 

Another theory proposes 
that the gaseous particles give 
off very short ether-waves, 
caused by their intramolecular 
vibrations, and by means of 
these waves stimulate the sen- 
sitive nerve-cells. In this case the kind of olfactory sensation 
aroused would depend upon the character of the intra- 
molecular vibrations, which in turn depend upon the vibra- 
tions of the atoms or groups of atoms within the molecule. 
It has been discovered that certain substances having similar 
molecular structure possess similar odors. But, on the 
other hand, some substances with widely different constitu- 
tions are similar in odor. At present it is impossible to 
make any thoroughgoing correlation between the molecular 
structure of odoriferous substances and the qualities of ol- 
factory sensations. However, some interesting facts have 
come out of the investigations into the chemical nature of 
odorous substances. For instance, it has been found that 
practically all odorous substances contain elements belonging 
to only three groups in the periodic system of classification 
(Mendelejeif's groups). They are the fifth, sixth, and sev- 



Fig. 45. — Diagram showing cells in 
regio olfactoria: a, olfactory cell, 
with h, projecting hairs; b, sup- 
porting cells; c, nerve-fibre. 



132 PSYCHOLOGY 

enth groups. If similar substances derived from the elements 
of one of these groups are arranged according to their molec- 
ular structure, their odors will form a series of related odors 
which shade off from one to the other. As an illustra- 
tion, we may arrange fatty acids in the following order: 
formic (CH2O2) ; acetic (C2H4O2) ; propionic (C3H6O2) ; butyric 
(C4H8O2); valerianic (C5H10O2); caproic (C6H12O2). The 
odors from these substances are similar, but change gradu- 
ally as we pass along the series. The higher acids formed 
from these elements (stearic, C18H36O2) have Httle or no 
odor.^ Chlorine, bromine, and iodine give ofi odors that can 
also be arranged in a series of similar experiences. 

Classification. — ^The fact that we know so little about the 
stimuli has stood in the way of classifying the many differ- 
ent olfactory sensations. The number of elementary olfac- 
tory qualities is unknown. As yet no satisfactory classifica- 
tion has been made. Whether all odors may be reduced to 
a few elementary kinds, or whether they must remain as 
they are now, a chaotic mass of sensory experiences, only 
the future will reveal. 

The classification of olfactory sensations into two kinds, 
agreeable and disagreeable, is based upon the feelings which 
accompany the sensations, and not upon the quality of the 
sensations themselves. It is therefore of little value. 

The modification of the Linnaeus table of olfactory groups 
by Zwaardemaker is practically the only classification of 
odors that we have at the present time: 

1. Ethereal Odors: Fruits, wine, ether, beeswax. 

2. Aromatic Odors: Spice, lavender and anise, lemon, 
cedar wood, rosewood, almond. 

3. Fragrant Odors: Flowers, vanilla, balsam. 

4. Ambrosial Odors: Musk and amber. 

5. Alliaceous Odors: Onion, asafoetida, dried fish, chlo- 
rine, iodine. 

' Haycraft, Brain, 1888, p. 166; 1889, p. 160. Schafer's "Text Book of 
Physiology," 1900, II, p. 1254. 



OLFACTORY AND GUSTATORY SENSATIONS I33 

6. Empyreumatic Odors: Burned substances, tar, gasoline, 
creosote. 

7. Hircine Odors: Cheese, rancid butter, lactic acid. 

8. Repulsive Odors: Narcotics, certain insects. 

9. Nauseous Odors: Decaying animal matter. 

The list is not complete. There are many odors which 
will not go under the nine headings, and it is evident that the 
different classes are not elementary in nature. At present 
the only hopeful indication of a successful classification of 
the olfactory sensations is the suggestion that substances of 
a similar chemical nature give similar odors. Something 
may be done by putting together in a single class all sensa- 
tions aroused by each group of closely related chemical sub- 
stances. By working over the field carefully the fundamental 
uniformities and differences in the qualities of olfactory sen- 
sations may be discovered. 

Many olfactory stimuli, besides arousing their own true 
olfactory sensations, excite also other concomitant sensa- 
tions which are blended with the olfactory sensations and are 
often confused with them. Ammonia, for instance, affects 
all parts of the mucous membrane in the mouth and throat, 
giving a stinging or tingling tactile sensation besides the 
smell proper. Likewise, nauseous stimuli arouse the sensa- 
tions of nausea, which are mixed with the true olfactory 
sensations. In the study of olfactory sensations these ac- 
companying sensory elements must be analyzed out and 
disregarded. 

The threshold of olfactory sensations is very low. A 
hound following the trail of game or his master's footsteps 
by the sense of smell, a bird-dog discriminating the different 
odors of ''live" and "dead" birds, suggest the delicacy of 
this sense. Man's olfactory sense is not so acute as that of 
the dog, but nevertheless it is sharp enough to detect slight 
traces of known substances too small to give chemical reac- 
tions. Camphor, i part to 400,000, and musk, i part to 
8,000,000, can be detected by the sense of smell. In order 



134 PSYCHOLOGY 

to be sensed at all, substances niust be composed of mole- 
cules having a certain minimum weight. There is some 
individual variation, but for most persons any substance 
whose molecules possess a weight less than those of prussic 
acid is odorless. 

Adaptation to olfactory stimuli takes place very rapidly. 
We soon fail to notice the odor of a badly ventilated room. 
Odors that are very marked at first gradually fade out if the 
stimulus is continued. If camphor-gum is held to the nos- 
trils for a few minutes the decrease in the intensity of the 
odor can be noticed before the end of the first minute. If the 
stimulus is allowed to act long enough, it will become in- 
odorous. One laboratory subject gave the following results: 
asafoetida became odorless in i minute and 17 seconds; pep- 
permint in 6 minutes; heliotrope in less than a minute; cam- 
phor in I minute and 34 seconds; iodine in 54 seconds. 

This adaptation of sense-organs to continued stimulation 
has sometimes been attributed to fatigue. But whether we 
have to do with a positive process of adaptation or a nega- 
tive one of fatigue is difficult to determine. 

The fact that, when the olfactory sense-organs become 
adapted to a certain odor, certain other odors also fail to 
arouse sensation, while others are sensed without impair- 
ment, indicates that different olfactory stimuli have similar 
physiological effects. This sameness of physiological effect 
might very well be taken as a suggestion for the classification 
of odors. Odors which have the same effect in fatiguing or 
adapting the sense-organ might be considered as belonging 
to the same class. If the nose is fatigued for iodine, it be- 
comes thereby fatigued also for alcohol, heliotrope, and pos- 
sibly other odors, while the odor of ethereal oils is not less- 
ened at all. 

It may be that the olfactory nerve-endings are differenti- 
ated, and that a given stimulus acts upon only one kind of 
end-organ, without affecting others. The phenomena in 
partial anosmia, a pathological condition in which the sub- 



OLFACTORY AND GUSTATORY SENSATIONS I35 

ject, while possessing in other respects normal olfactory sen- 
sations, is lacking in ability to sense certain odors, point 
also to differentiated end-organs. It is, however, improb- 
able that certain nerve-endings are set apart for a certain 
kind of stimulus alone; rather, if there is differentiation, it is 
simply that certain nervous elements in the olfactory region 
are more sensitive to some odors than to others. 

Many of the great variety of odors which we experience 
are the result of combination and fusion of odors. Odors 
may combine in such a way that we are able to detect the 
presence of each one in the combined result. Or odors may 
fuse and form a new odor, in which the component parts are 
not detected. Under some circumstances certain odors will 
not combine or fuse, but rather suppress each other. For 
instance, the odor of carbolic acid suppresses the odor of 
putrefaction. If two different odors which suppress or "com- 
pensate" each other are presented through the olfactometer, 
one to each nostril at the same time, the phenomenon of 
rivalry is set up. We sense first one and then the other 
alternately. Contrast effects are also present among odors. 
For instance, it has been found that after smelHng cedar 
wood for a short time the odor of india-rubber becomes notice- 
ably more distinct. 

Sensations of smell are very rich in associations. They 
are also effective in arousing feelings, moods, and emotional 
attitudes. The fact that incense plays an important part 
in certain religious rites and ceremonies is interesting in this 
connection. The aesthetic value of perfumes is due to the 
relation of sensations of odors and the feelings. 

It is thought that the sense of smell is degenerating in 
man. It is pointed out that man's sense of smell is much 
less acute than that of the lower animals, and that while the 
olfactory lobes, the lower centre for smell, make up the larger 
part of the brain in some of the lower animal forms, in man 
they have dwindled into insignificance. Certainly, in man, 
the importance of this sense has become relatively less promi- 



136 PSYCHOLOGY 

nent. To the animal that must track its prey or scent the 
presence of its enemies, or find its mate, it is the chief food- 
getting and race-propagating sense. But man has risen 
above this primitive method of sense-guidance, and has come 
to depend more and more upon the more highly developed 
senses. The olfactory sensations, however, still stand guard 
over the selection of foods and aid in the detection of noxious 
and injurious surroundings. They also contribute no incon- 
siderable part to the character of what we ordinarily con- 
sider the sense of taste. Taste and smell are so closely 
related that without critical psychological analysis we fail 
to discriminate the elements supplied by the sense of smell 
to the complexes which masquerade under the name of taste. 

Gustatory Sensations 

On account of the very close relation between the sen- 
sory experiences which come from the nose and the mouth, 
and because the tongue surface is also capable of giving rise 
to sensations of pressure, temperature, and pain, as well as 
gustatory sensations, we rarely ever experience the quality 
of taste alone. Our so-called sensations of taste are com- 
plexes of taste proper, smell, tactile, temperature, and in 
some cases weak pain sensations. It is a common observa- 
tion that while we are suffering from a severe cold in the 
head we lose most of our taste-sensations. It is not taste 
proper, however, but the odor of food substances which is 
lost, and which we have confused with taste because it blends 
so closely with it. All substances taken into the mouth 
excite tactile sensations. Temperature is usually present, 
and a few substances, Hke charged beverages, arouse slight 
pain-sensations. So, ordinarily, what we accept as taste is 
a compound of several kinds of sensations. It is a difficult 
task to analyze out of these complexes the true sensations of 
taste. 

If the nostrils are stopped so that no air passes through 
them, one is unable to taste the difference between many dif- 



OLFACTORY AND GUSTATORY SENSATIONS I37 

ferent substances, such as tea, coffee, solutions of quinine, 
etc. The subject should be blindfolded and the solutions 
should be of equal strength, but not strong enough to arouse 
tactile sensations by the astringent quality of the solutions. 
The student will be surprised to find how blunted apparently 
the sense of taste is when smell is eliminated. Much of the 
flavor of fruits, the bouquet of wines, and many other so- 
called taste qualities are contributed by the sense of smell. 

End-Organ. — The end-organs for gustatory sensations are 
the taste-buds found chiefly in the papillae of the tongue, but 
also on the surface of the soft palate, the fauces, and epiglot- 
tis, and even in the larynx. Taste-buds are small oval bodies 
resembling a bud in structure and occupying little pit-like 
cavities in the epithelium. These cavities open out into 
the mouth through small apertures called "gustatory pores." 
Through these pores food substances in solution enter and 
stimulate the taste-buds. The highly modified epithelial 
cells which make up the taste-bud are of two kinds, the 
supporting cells — long and tapering — and the gustatory cells 
which occupy the more central part of the taste-bud. The 
gustatory cell is a spindle-shaped cell whose outer end termi- 
nates in a fine, hair-like process which projects through the 
gustatory pore. It was formerly thought that its inner end 
was continuous with a true nerve-fibre, but this is not true. 
The sensory nerve-fibres enter the base of the taste-bud 
and, dividing into many branches, end about the body of 
the gustatory cell. Outside the taste-buds are found other 
nerve-endings which minister to the cutaneous sensations of 
pressure, cold, warmth, and pain, which are also present in 
the mouth surfaces. On the tongue the taste-buds are found 
on the sides of the circumvallate papillae, in the fungiform 
papillae, and in the furrows between them. The filiform 
papillae do not contain taste-buds. It is estimated that 
there are from 100 to 200 taste-buds in each one of the cir- 
cumvallate papillce. 

The gustatory cells are without doubt the sensory end- 



138 



PSYCHOLOGY 




organs. The hair-like processes are stimulated by the solu- 
ble substances. The impulses set up are communicated 
through the body of the cell to the endings of the sensory 
fibres which terminate about these cells. 

.^ Gustatory Nerves and Brain Centres. — 

The back part of the tongue, the location 
of the circumvallate papillae, is supplied by 
sensory fibres from the glosso-pharyngeal 
or ninth cranial nerve, w^hile the front part 
receives sensory fibres from the lingual 
branch of the trigeminal or fifth nerve. So 
far as can be determined, the cortical cen- 
tres for gustatory sensations are in the inner 
sides of the hemispheres in the hippocampal 
lobes, near but posterior to the olfactory 
centres. 

Stimulus. — All gustatory stimuli must 
be soluble. A perfectly insoluble substance 
is tasteless. It does not follow, however, 
that all soluble substances have taste; some 
do not. A sapid substance, not in liquid 
form, may dissolve in the saliva after being 
taken into the mouth, and so reach the 
taste-buds, where it sets up a chemical 
change. There seems to be no consistent 
relation between the chemical nature of substances and the 
taste-sensations which they arouse. Substances of very dif- 
ferent chemical constitution arouse the same taste-sensations. 
The question of whether mechanical stimulation of the 
tongue arouses taste-sensations is in dispute. Apparently 
vague sensations of taste can be aroused by tapping the tip 
of the tongue. There is no doubt of the fact that electric 
currents passed through the tongue excite taste-sensations. 
The positive pole of a battery tastes decidedly sour and the 
negative pole is slightly bitter. Whether this is due to the 
direct effect of electricity upon the taste-buds, or is the 



Fig. 46. — Diagram 
showing a taste- 
bud and the 
nerve-endings :n, 
nerve - fibre, a, 
gustatory pore; 

b, gustatory cell; 

c, supporting cell. 
(Ret^ius.) 

(From Quain's "Ele- 
ments of Anatomy.") 



OLFACTORY AND GUSTATORY SENSATIONS 1 39 

result of electrolysis in the saliva which might free acid and 
alkaline ions, is not known. 

Classification of Gustatory Sensations. — The gustatory 
sensations may all be reduced to four elementary or simple 
sensations : 

1. Sweet. 

2. Sour. 

3. Bitter. 

4. Saline. 

Alkaline and metallic sensations have been proposed, also, 
as elementary taste-sensations, but they are thought by some 
experienced observers to be compounds: alkaline being a 
combination of salt and sweet, and metallic of salt and sour. 
Even sweet, sour, bitter, and saline sensations, as we know 
them in our ordinary taste experiences, are not simple or 
pure. The sensation aroused by salt has, in addition to its 
taste, a slight burning sensation which is tactual in its origin. 
The tactile sensation may be aroused alone by solutions of 
salt too weak to arouse the taste of salt. Sour or acid sen- 
sations have an astringent quality which is not due to taste. 
Sweet has a smooth, almost oily quality, which can be iso- 
lated, as can the other non-gustatory qualities mentioned, 
by applying the stimuli to tasteless regions of the mouth — 
the middle of the tongue or the hard palate. 

Whether the four elementary gustatory sensations have 
special taste-buds in each case is not known. We do not 
know definitely whether an individual taste-bud will respond 
to only one or to four kinds of stimulation, and so produce 
the nerve-excitation for one or for four kinds of sensation. 
We do know that there is a partial surface differentiation of 
the tongue for the four taste qualities. For instance, the 
circumvallate papillae at the base of the tongue are more 
sensitive to bitter than to the other qualities. The tip of 
the tongue is more sensitive to sweet and salt and less sen- 
sitive to sour and bitter, while the sides of the tongue are 
especially sensitive to sour. (The central portion of the 



I40 PSYCHOLOGY 

tongue in adults has been found completely lacking in taste- 
sensations, although possessing those of the pressure, ther- 
mal, and pain senses.) Some experimental results of stimu- 
lating individual papillae with sweet, sour, bitter, and saline, 
indicate that the taste-buds may be differentiated. It has 
been found, for instance, that some of the papillae respond 
to only one kind of stimulation, others to two, others to 
three, and still others to all four.^ Where a single papilla 
gives out only one kind of sensation, it seems probable that 
it contains taste-buds of one kind only. Pathological cases 
of partial ageusia, or loss of taste, have been reported in 
which one or two of the taste qualities are lacking, while the 
others are not affected. Certain drugs will destroy some of 
the elementary gustatory sensations without interfering with 
the others. The leaves of the plant gymnema sylvestre will, 
when chewed, cause the loss of sensations of sweet and bit- 
ter, while salt and sour remain. If a proper solution of co- 
caine is placed upon the tongue it will affect the taste-sensa- 
tions separately: first bitter is lost, then sweet, then salt, and 
finally sour. Another fact of interest in this connection is 
that some substances will arouse different tastes on different 
parts of the tongue; sodium sulphate is salty to the tip and 
bitter to the base of the tongue, while a certain form of sac- 
charine is sweet to the tip and bitter to the posterior part of 
the tongue. All these facts would not be difficult to explain 
if we were certain that the taste-buds are differentiated, so 
that a single bud responds with only one kind of sensa- 
tion. 

Retardation. — The initial period of retardation differs 
slightly for the four qualities of taste-sensations. Salt is the 
quickest and bitter the slowest in responding after the stim- 
ulus is applied. This may be due either to the chemical 
nature of the stimulus, or to the manner in which the end 
organs respond, or even to the central cortical processes. 

iQehrwall: Skandinavisches Archiv f. Physiol., 1890, II, p. i. Kiesow: 
" Wundt's Philosoph. Studien," 1898, XIV, p. 591. 



OLFACTORY AND GUSTATORY SENSATIONS I4I 

Mixtures, Contrasts, Adaptation. — The mixing of two 
taste-stimuli may result, in some cases, in the sensations re- 
maining separate and distinct from each other, although 
both are present in consciousness; in others, the sensations 
may alternate, first one and then the other appearing, or 
they may tend to neutralize or compensate each other. Salt 
and bitter, if not too intense, may exist side by side. If, 
however, the intensities of taste-sensations are high, there 
is a tendency toward rivalry. The neutralization or com- 
pensation of tastes is very familiar: the taste of sugar will 
neutralize the bitter taste of coffee, or the sour taste of claret. 
There seems, however, rarely to be a complete neutralization 
between compensating tastes. The nearest approach is that 
set up between sweet and salt. If salt is added to a weak 
sweet, an insipid, flat taste, neither sweet nor salt results, 
which amounts almost to the absence of taste-sensation. 
Compensation is least noticeable between sweet and sour, 
while salt and bitter, sour and bitter, sour and salt, and 
sweet and bitter manifest it in increasing degrees as we pass 
from one pair to the next. There is sometimes a marked 
degree of neutralization between tastes and smells; the nau- 
seating odor of castor-oil is offset by the sour taste of lemon- 
juice, or the bitter taste of quinine is partially neutralized by 
the aromatic odor of essence of orange-peel. 

Contrast effects are also present in gustatory sensations. 
The sour taste of fruit appears more intensely sour after 
honey has been taken into the mouth. Contrasts (both 
simultaneous and successive) may be observed between salt 
and sour, and salt and sweet. If the tip of the tongue is 
stimulated first with a salt solution, then thoroughly rinsed 
and dried, a very weak solution of sweet, which cannot be 
tasted normally, tastes decidedly sweet. Even distilled 
water, which is ordinarily tasteless, will appear sweet after 
salt stimulation. Salt appears to bring out the sweet. The 
same effect may be obtained by simultaneous stimulation of 
the two sides of the forward part of the tongue: salt applied 



142 PSYCHaLOGY 

on one side will increase the effect of a weak solution of sweet 
on the other. Contrast effects in bitter have not been estab- 
lished. A bitter sensation which lies just below the threshold 
cannot be brought out by simultaneous stimulations of sweet, 
sour, or salt. 

Adaptation of the sense-organs of taste is not as marked 
as in the case of the olfactory sense. It is, however, notice- 
able in our every-day experiences. Food which at first seems 
very sweet will, if we continue to eat it, decrease in intensity. 
A solution of salt will appear less salty as we continue to taste 
it. It may be that some of the successive contrast effects 
mentioned above are due to adaptation. When, for in- 
stance, the sour of fruit is increased after honey is eaten, the 
adaptation of the sense-organs to the honey may make them 
less able to taste the sweet in the fruit and, consequently, its 
acid quality will stand out more plainly. 

Threshold. — The temperature of sapid substances affects 
the threshold of gustatory sensations. Extremes of cold and 
warm lessen the sensitiveness of the taste-organs. To get the 
maximum effect, taste-stimuli should be of moderate tem- 
peratures. Hot soups and cold beverages sacrifice the true 
gustatory sensations, and minister to the tactile and tem- 
perature-sensations in the mouth, and the olfactory sensa- 
tions in the nose. The total complex effect may be enhanced, 
but taste-sensations are lessened thereby. What the weak- 
est sensation of taste is for any given substance can be de- 
termined only by the strength of solution necessary to arouse 
a just perceptible taste-sensation. The salt of sodium chlo- 
ride can be tasted upon the tip of the tongue when the solu- 
tion is 0.25 gm. to ;oo c.c. of water; sweet of gugar on the 
tip of the tongue, 0.50 gm. to 100 c.c. of water; bitter of 
quinine on the base of the tongue, 0.00005 S^- to 100 c.c. of 
water; sour of hydrochloric acid on the sides of the tongue, 
0.007 &^- to 100 c.c. of water. There are some individual 
variations among different subjects, but these results hold 
for any one having a fairly acute sense of taste. 



OLFACTORY AND GUSTATORY SENSATIONS 1 43 

Complexes. — In the beginning of this discussion we called 
attention to the blending of sensations of taste, smell, tactile, 
temperature, and pain sensations. Before leaving the sub- 
ject we may again call attention to the need of critical psy- 
chological analysis when dealing with the so-called tastes of 
every-day life. Some of these so-called tastes are really not 
tastes at all. The pungent " tastes" of spices are almost alto- 
gether odors, astringent tactile sensations, and temperature- 
sensations, sometimes mixed with slight intensities of pain. 
Tea and coffee owe their distinguishing characters to odor 
and astringent tactile sensations. Many food substances, 
like nuts and vegetables, are distinguished in the mouth by 
their consistency, which appeals to pressure-sensations. Pep- 
permint is hardly a taste at all; there is very little left when 
the sensations of cold and smell are eliminated. The so- 
called oily tastes are tactile in nature. 

This tendency of sensations to blend and combine into 
complex experiences is present everywhere in the sensory 
realm, but the taste and smell sensations furnish such a 
striking illustration of the coalescing nature of consciousness 
that it is well to emphasize the point at this time. 



CHAPTER VII 
AUDITORY SENSATIONS 

Auditory sensations belong to two great groups: sensa- 
tions of noises and sensations of tones. Noises are caused 
by the irregular, non-periodic vibrations of air particles set 
up by objects in the outer world. Tones, on the other hand, 
are caused by regular, recurrent, periodic vibrations of air 
particles. Here, as in all the other sense realms, the real 
elementary qualities of sensations are obscured in every-day 
experience by the combinations and complexes in which they 
appear. For instance, the apparently simple sound of a 
single piano note is made up of at least two or more discrim- 
inable tonal sensations, which we can isolate with a little 
practice in careful observation. In order, then, to get at the 
component elements of our experiences of sound, we must 
analyze these experiences critically. In the case of auditory 
sensations we can make a much larger use of the knowledge 
of physics than we have heretofore. Happily, the physicist's 
knowledge of the nature of the stimuli for the sense of hear- 
ing — resounding bodies and the air-waves which they propa- 
gate — is of great value in breaking up the compounds of 
auditory consciousness into its elements. We are further 
aided by the advanced stage of physiological and anatomical 
knowledge of the inner ear — the sense-organ of hearing. 

End-Organ. — The inner ear is a twofold organ of sense. 
One part of it, the cochlea, transforms air-vibrations into 
sensations of sound; another part, the vestibule and the 
semicircular canals, yields sensations of movement and 
equilibrium. This latter part we have already treated under 
kinaesthetic sensations. It is, therefore, the cochlea, the 
winding snail-shell of the ear, that commands our attention 

144 



AUDITORY SENSATIONS 



145 



as the organ of hearing proper. The outer ear, composed 
of the pinna and the external auditory canal, and the middle 
ear [shut off from the external ear by the tympanic mem- 
brane, or drum, and containing small ear-bones {malleus, 
incus, and stapes) controlled by two small muscles (tensor 




Fig. 47. — Semidiagrammatic section through the right ear (Czermak). G, 
external auditory canal; T, tympanic membrane; F, tympanic cavity; 0, 
fenestra ovalis; r, fenestra rotunda; B, semicircular canal; S, cochlea; Vt, 
scala vestibuli; Pt, scala tympani; E, Eustachian tube. 
(From Howell's "Text-Book of Physiology.") 



tympani and stapedius)] simply furnish the means of trans- 
mitting air-vibrations from the outer world to the auditory 
nerves in the cochlea of the inner ear. The middle ear opens 
into the upper and back part of the mouth-cavity through 
the Eustachian tube, whose function it is to equalize the air- 
pressure on both sides of the tympanic membrane. 

The outer shell or pinna of the ear receives the air- waves \ 
and conducts them inward through the external auditory 
canal. It is probable that the air-waves are modified some- 
what by the structure of the outer ear, the shorter waves 



146 PSYCHOLOGY 

being strengthened and the longer waves lessened in ampli- 
tude. The ear-drum is a thin membrane, slightly funnel- 
/ shaped, with its apex turned inward. The three ear-bones, 
' or ossicles, articulated together, stretch across the cavity of 
the middle ear from the ear-drum to the oval window of the 
inner ear, into which one of them — the stapes — fits. The 
two small muscles which attach to the ear-bones control, 
through the lever-like action of the bones, the tension of 
the ear-drum, thus adjusting it to a large range of tonal 
vibrations. It is supposed by some that air-vibrations are 
communicated from the ear-drum to the fluid — the peri- 
lymph — of the inner ear by means of the mechanical piston- 
like action of the ear-bones, which act in such a manner that 
the vibrations of the ear-drum are intensified at the oval 
window of the vestibule. But cases of persons whose ear- 
bones have been destroyed or removed by surgical operation, 
and who can, nevertheless, hear sufficiently well to carry on 
a conversation, prove that the vibrations may be carried 
across the middle ear-cavity without the aid of the ossicles. 
Vibrations may also reach the inner ear through the bones 
of the skull. If the ears are stopped, a feebly sounding 
tuning-fork cannot be heard; but if its base is pressed against 
the head, it can be heard distinctly. The ticking of a watch 
which cannot be heard with the ears stopped becomes audi- 
ble when placed between the teeth. 

The inner ear is composed of the bony labyrinth, an 
intricate chamber hollowed out of the temporal bone. Within 
the chamber lies the membranous labyrinth, a closed, irregu- 
larly shaped sac which fits very loosely to the walls of the 
bony chamber, and is separated from it by the perilymph, 
the fluid which fills the spaces outside the sac. The sac 
itself is filled with a fluid called the endolymph. 

The vestibule is the central cavity of the bony labyrinth 
and opens out into the semicircular canals behind and into 
the cochlea in front. It communicates with the middle ear 
by means of the oval window {fenestra ovalis), into which 



AUDITORY SENSATIONS 



147 



the base of the stapes fits. From the lower part of the 
cochlea another opening {fenestra rotunda) closed by a thin 
membrane leads into the middle ear. The parts of the mem- 
branous labyrinth are the utriculus, which, opens into the 




Atedu 
Ductus Endolymphaticus 
Fig. 48. — The membranous labyrinth (enlarged). 

semicircular canals, the sacculus and its indirect connection 
with the utriculus, and the membranous cochlea. 

The bony cochlea, a spiral canal which winds two and 
one-half times about its axis, • or modiolus, contains three 
membranous canals: the scala vestibuli, the scala tympani, 
and the scala media. 

The scala vestibuli communicates with the perilymph in 
the vestibule and carries the vibrations set up there along its 
length to the apex of the cochlea, where it communicates 
through a small opening with the scala tympani, which de- 
scends to the base of the cochlea. Here the scala tympani 
ends at the round window. If the vibrations which have 
travelled the length of these tubes have not already spent 
their force, they are cushioned against the flexible membrane 
of the window. It is supposed that this acts as a safety 
device by lessening the force of the too powerful vibrations, 



148 



PSYCHOLOGY 



which might injure the delicate specialized cell-structures of 
the inner ear. The scala media, or canal of the cochlea, lies 
between the scala vestibuli and the scala tympani, but does 
not communicate with them. On the floor of the scala media 




Fig. 49. — Longitudinal section of the cochlea. S.V., scala vestibuli; S.T., scala 
tympani; M, scala media; G, cochlear ganglion; C.N., cochlear nerve. 



are found the special organs of hearing: the basilar membrane, 
the rods of Corti, and the hair-cells. About these specialized 
cells, the fibres of the auditory nerve end. The canal of the 
bony cochlea is partly divided into upper and lower halves 
by a bony shelf. The basilar membrane stretches from the 
free edge of this shelf across to the outer wall of the cochlea 
and so makes the partition complete and at the same time 
forms the floor of the scala media, upon which the rods of 
Corti and the hair-cells rest. Another membrane {membrane 
of Reissner) stretches from the bony shelf to the upper wall 
of the canal forming the roof of the scala media and separat- 
ing it from the scala vestibuli. (See Fig. 50.) 

The basilar membrane, forming the floor of the spiral 



AUDITORY SENSATIONS 



149 



canal, is composed of short, transverse fibres, which reach 
from the shelf to the outer wall. Due to the fact that the 
spiral shelf becomes narrower as it ascends, the fibres of 
the basilar membrane become longer toward the apex of the 
cochlea. The number of basilar fibres is estimated at 24,000. 



Cochlear ' 
Nerve 




Ftg. 50. — A transverse section of the cochlear tube. 



The rods of Corti form two rows of rod-like cells, which 
stand upon the basilar membrane, and since the outer and 
inner rods lean toward each other and unite at their tops, 
they enclose a tunnel {canal of Corti) which extends the 
whole length of the cochlea. The rods of Corti are com- 
puted to be 9,500 in number. 

The hair-cells lie on both sides of the rods of Corti. They 
consist of rows (one inner and four or five outer rows) of 
column-like cells which run parallel to the rods of Corti. 
The hair-cells bear short, stiff, hair-like processes upon their 
upper extremities. 

The nerve-fibres of the cochlear branch of the eighth or 
auditory nerve pass through openings in the bony substance 
of the spiral lamina and, entering the scala media at the base 



I50 



PSYCHOLOGY 



of the hair-cells and rods of Corti, they terminate by arbor- 
ization about these cells. In spite of the rather accurate 
knowledge we have of the structures in the canal of the 
cochlea, we are not able to determine which of these is 
directly responsible for the excitation of the nerve- endings. 
It is plain that vibrations set up in the fluid of the vestibule 




Nerve'fibres Inner rod Outer rod Basilar membrane 

Fig. si. — The organ of Corti. 
(From Ladd and Woodworth, after Retzius.) 



would, in passing up the scala vestibuli be communicated 
through the membrane of Reissner to the fluid in the scala 
media and set up vibrations of the basilar membrane and 
the hair-cells which rest upon it. What is needed, however, 
to explain the physiological basis of hearing is some appa- 
ratus which will act not as a whole but will respond in parts, 
or in different modes to different kinds of vibrations. The 
many different tonal qualities which the ear can detect call 
for a high degree of differentiation in the end-organs, in 
order that different nerve - impulses, corresponding to the 
different sensory qualities in consciousness, may be sent to 
the brain. The "sympathetic-resonance theory" "of Helm- 
holtz has been very widely held. He first suggested that 
the rods of Corti were responsible for our tonal discrimina- 
tion, but he abandoned this theory because it was demon- 



AUDITORY SENSATIONS 151 

strated that in birds the rods of Corti were lacking. Fur- 
ther, they were not numerous enough to account for the 
number of tonal qualities; and in addition they do not differ 
sufficiently in size and structure. He then accepted the sug- 
gestion of Hensen that the fibres of the basilar membrane, 
which differ in length, were capable of vibrating sympatheti- 
cally with the different vibrations of the fluid of the ear. 
He found, therefore, in the basilar membrane a harp with 
its different strings tuned for different vibrations. The 
physics of this theory may be demonstrated very simply by 
lifting the dampers from the strings of a piano and singing a 
tone into them; the vibration of the voice will set in vibra- 
tion sympathetically only that string which is tuned to the 
tone sung. So, thought Helmholtz, the different fibres vi- 
brate sympathetically and selectively to the vibrations con- 
veyed to it by the mechanism of the ear. There are some 
objections to the theory on the ground that the fibres cf 
the basilar membrane are so extremely short and vary in 
length so slightly that they could not be thought of as reso- 
nators, or "vibrating strings." Moreover, if they do vibrate, 
the range of vibration would be too limited to account for 
the wide range of tonal differences. Recently Hardesty^ has 
discovered that the fibres of the basilar membrane are bound 
together by cross-fibres in such a way that it seems improb- 
able that they could vibrate individually. 

Many other theories of audition have been proposed. 
The most noteworthy is the "telephone theory."- This 
theory holds that every rate of vibration sets up vibrations 
in the organ of Corti as a whole, affecting the adjacent hair- 
cells. The rate of vibration is transmitted to the nerve-cells 
and through them telephoned to the brain, where they are 
interpreted in terms of tonal sensations. According to this 
theory, the analysis of the stimulus takes place in the brain- 
cells, rather than in the end-organs, as is assumed in the 
Helmholtz theory. 

^ American Journal of Anatomy, 1908, VIII, p. 109. 

- Rutherford: "The Sense of Hearing," Lancet, 1887, I, pp. 2-6. 



152 PSYCHOLOGY 

Brain Centres. — The cortical centre for hearing is in the 
superior convolutions of the temporal lobes. ^ Complete 
deafness follows the destruction of both temporal lobes. In 
cases of lesion in one temporal lobe, partial deafness in the 
opposite ear follows. Sometimes when the lesion is not ex- 
tensive or is located in neighboring areas, there is merely 
a disturbance of hearing, or a loss, not of the sensations of 
hearing, but of their associations, as in *' word-deafness" (in- 
ability to understand spoken words) . In this case the sounds 
are heard, but their meanings have been lost. In right- 
handed persons this occurs when the lesion is located in the 
left lobe. Since complete destruction of the auditory centre 
on one side does not cause complete deafness in the opposite 
ear, it would appear that not all of the fibres from one ear 
cross to the opposite side of the brain, but rather that each 
ear sends fibres to both sides of the brain. The path of the 
auditory impulses is roughly from the ear to the nuclei in 
the upper part of the medulla; from there by a second set of 
neurones they cross over to the opposite side of the medulla, 
thence by a third set of neurones to the internal geniculate 
and inferior quadrigeminum of the mid-brain, and from 
there by a fourth set of neurones to the temporal lobe. The 
pathways by which the two branches of the auditory nerve 
(the vestibular and cochlear) reach the brain are as distinct 
as their distribution in the ear, which is, of course, evidence 
for the difference in function of the two parts of the inner 
ear. The fibres of the vestibular branch pass from the semi- 
circular canals to a nucleus (near the nuclei for the cochlear 
fibres) in the medulla, from there a second set of fibres crosses 
over to the opposite side of the medulla and go to the cere- 
bellum. 

The Stimulus. — Air-waves set up by vibrating bodies are 
the normal stimuli for auditory sensations. These air-waves 
may vary in length, in amplitude, and in form. The shorter 
the wave the quicker the rate of vibration. For instance, 

1 See Figure 28. 



AUDITORY SENSATIONS 



153 




(o) Simple Harmonic Wave 



(6) Simple Harmonic Wave 



the short wires of the piano give a short wave-length and a 
very rapid rate of vibration per second, c^'s vibration rate is 
1,024 vibrations per second. On the other hand, the long 
wires give a longer wave- 
length and a slower rate of 
vibration per second; Go's 
vibration rate is 64 vibra- 
tions per second. The 
length of the air-wave (or 
the rate of vibration) de- 
termines the pitch of the 
sound. Variations in the 
amplitude of a given wave- 
length correspond to the 
variations in the intensity, 
or loudness, of the result- 
ing sound. The form of 
the air- wave determines 
whether the resulting 
sound-sensation is simple 
or compound. The peri- 
odic simple harmonic 
waves give simple tones, 
while the periodic com- 
pound harmonic waves 
give compound or compos- 
ite tones, or clangs, as they 
have sometimes been 
called. 

Most vibrating bodies 
give out compound waves. This is due to the fact that 
they are capable of vibrating not only as wholes, but also 
in parts. A string, for instance, vibrates not only in its 
entire length, but also in halves, thirds, fourths, etc., each 
part vibrating at the same time, but at different rates. 
The halves execute twice as many vibrations as the whole 




(c) Compound Harmonic Tl'aie^ 
Resultant of (a) and (6). 



Fig. 52. — Both {a) and {b) represent 
simple harmonic waves of different 
lengths; {h) is one-half the wave- 
length of (a), but its rate of vibration 
is twice that of (a). These waves, 
when acting separately, produce sim- 
ple tones which differ in pitch. When 
they act together the resultant wave 
is represented by (c) a compound 
harmonic wave, producing a compound 
tone, composed of the two tones cor- 
responding to waves (a) and (&). 



154 PSYCHOLOGY 

string, the thirds three times, and the fourths four times as 
many. All these vibrations produce a resultant air-wave of 
the compound type, which form of stimulus arouses a com- 
pound tone. A compound wave may therefore be treated 
as a composite of simple waves, and the resulting compound 
tone as a complex of pure tones. Periodic waves (simple or 
compound) are so termed because they repeat the same 
movements, while non-periodic are irregular. 

The . normal manner for sound-vibrations to reach the 
inner ear is through the external ear, tjnnpanic membrane 
and ossicles of the middle ear to the fluid of the vestibule. 
But we have already mentioned the fact that sound-stimuli 
may reach the inner ear by conduction through the bones of 
the skull. It is practically impossible to excite the end- 
organs of one ear without at the same time aflfecting those 
in the other ear; for even if one ear is completely stopped, 
the stimulus may be conducted to it through the skull-bones 
or through the Eustachian tubes. 

Noises. — The difference in the mental qualities of noises 
and tones seems to be so great that it has been suggested 
that they must arise from different end-organs. Accordingly, 
attempts have been made to find other structures than those 
in the cochlea to which noise could be attributed. The sac- 
cule of the vestibule was supposed to be that structure. If, 
however, noises and tones have their origin in different end- 
organs, it is very probable that there would be pathological 
cases reported in which ability to hear noises would exist 
together with tonal deafness, or that noises would be lost and 
tones retained. But no such cases have been reported. 
Careful observation reveals a closer relationship between 
noises and tones than might be supposed. Certain noises 
reveal tonal qualities. The hum of street noises, the drone 
of the waves, the buzz of many voices, or even the pop of 
a pistol possess slight tonal qualities. On the other hand, 
many closely related tones, if sounded at the same time, 
produce a noise. Strike a dozen or more adjacent keys of 



AUDITORY SENSATIONS 1 55 

the piano simultaneously and note the effect. A single in- 
stantaneous exposure of a vibrating tuning-fork may be heard 
not as a tone but, if the exposure is short enough, as a noise. 

Noises may be divided into two classes: (i) the momentary 
or explosive noises, and (2) the continuous noises. Of the 
first class we have such noises as are represented by the 
words "crackle," "crack," "snap," "pop." Of the second 
class we have the hissing, roaring, rumbling sounds.^ No 
success has met the efforts to further analyze these complex 
noise experiences into their elementary sensory qualities. 
How many simple noise qualities there are has not been 
determined. 

If we accept the Helmholtz theory that simple tones are 
the result of the vibration of single fibres in the basilar mem- 
brane, we might further assume that noise arises when a 
large number of adjacent basilar fibres are set simultaneously 
vibrating, i. e., while simple tones come from the stimulation 
of single fibres (or a series of properly related fibres), noises 
result from the stimulation of the basilar membrane as a 
whole, or in large sections or blocks. 

Tones. — Tones constitute a continuous series of con- 
stantly changing sensory qualities from the lowest notice- 
able pitch to the highest. The change in pitch corresponds 
to the change in the vibration rate of the stimulus. The 
lowest tone that can be heard varies somewhat in different 
individuals, but lies between 20 and 28 vibrations per second, 
while the highest tone corresponds to vibration rates of from 
22,000 to 43,000 vibrations. Some investigators report in- 
dividuals who can detect tones from vibration rates as high 
as 50,000. The average, however, is about 32,000 vibra- 
tions. The extreme limits of tonal hearing may safely be 
put at 16 vibrations for the lowest tone and 50,000 vibra- 
tions for the highest tone.^ In old age, the end-organs for 

^Titchener: "Text-Book of Psychology," p. 95. 

^ The upper Hmit of tonal hearing may be determined by the Galton whistle, 
an instrument found in any psychological laboratory. The lower limit is 
determined by means of large tuning-forks. 



156 PSYCHOLOGY 

tone become less responsive, restricting the range of tonal 
qualities both at the higher and lower limits. Between the 
highest and lowest tone, there are for the human ear over 
11,000 discriminable tones. The ordinary musical scale, 
however, makes use of only about 100 tones lying at the 
lower part of the series; 88 of these tones and half-tones are 
represented on the keyboard of the grand piano, from A2 — 
26.6, to c^ — 4,096 vibrations. 

The ability to detect differences in pitch is not the same 
for all parts of the scale, but in its middle part — from c^ to c^ 
(256 to 512 vibrations) — the average, unpractised ear can 
sense a difference in pitch corresponding to a difference in 
the stimulus from 8 to 16 vibrations. This may be reduced 
by practice. Trained musicians have detected a difference 
of one- third of a vibration. Some individuals are extremely 
insensitive to differences of pitch. Cases have been reported 
where a difference of 64 vibrations (two whole tones on the 
musical scale) cannot be distinguished. The ability to dis- 
tinguish differences in tones must not be confused with the 
ability to "sing in tune." A singer who is able to detect a 
difference of one-half vibration may not be able to control 
the pitch of his voice within the limits of 8 vibrations or a 
quarter of a tone. 

When different notes are struck on a musical instrument, 
we usually determine the pitch of each note relatively, by 
referring the given tone to a standard tone whose place in 
the scale we already know. Given this standard, we can 
name any other tone by reference to the standard. There 
are some few individuals, however, who seem to possess 
what is known as ^'absolute pitch.^' They are able to judge 
absolute tone, which is quite different from determining dif- 
ferences in the pitch of two tones or in judging the interval 
between them. In absolute pitch there must be a very 
close and definite association between the tonal quality and 
the name of the tone, which is not present in the majority 
of musicians. 



AUDITORY SENSATIONS 157 

A certain form of tone-deafness may produce what are 
known as tonal gaps and tonal islands. These cases may 
appear when the outer and middle ears are perfectly normal, 
thus indicating the absence of certain specialized end-organs 
for tone. It may happen that although the range of tonal 
qualities is as great as usual, certain groups of tones cannot 
be heard, making a gap in the otherwise normal tonal series. 
Or, in other cases, only a few of the tones may be heard, 
while those above and below this group are absent, making 
a "tonal island." Such phenomena furnish further evidence 
of distinct end-organs for different tones. 

Compound Tones. — Only a few specially constructed in- 
struments are capable of producing simple tones, or at least 
tones that approximate simple tones. The tuning-fork is 
one of these. It produces a simple pendular wave and con- 
sequently a simple tone. Nearly all resounding bodies, even 
the vocal cords, give non-pendular or complex waves and 
arouse complex tones. When a single note is sounded by 
the voice, piano, violin, etc., what appears to the untrained 
ear as a single tone can, by careful observation, be analyzed 
into several simple tones, called partial tones, sounding simul- 
taneously. The lowest partial — the most dominant or in- 
tense tone — is the fundamental tone, and the others are the 
upper partials, sometimes called overtones. These upper par- 
tials are caused by the fact, already mentioned in the dis- 
cussion of sound-stimuli, that resonant bodies vibrate in 
parts as well as in wholes. The fundamental arises from 
the vibration of the whole body, while the upper partials 
arise from the vibrations of its respective parts. If, for in- 
stance, the wire of a "sonometer" (a long wire stretched on 
a resounding box) is struck with the sound hammer, it will 
vibrate as a whole, in halves, in thirds, in fourths, etc. Each 
part will give out its own simple tone, so that the tone that 
is heard is compound, made up of the fundamental tone 
(from the whole wire), the second partial (from the half 
wire), the third partial (from the third of the wire), the fourth 



158 PSYCHOLOGY 

partial (from the fourth of the wire). Other partials may 
be present, but they are very faint. The intensity of the 
partials wanes as the parts of the wire from which they arise 
become shorter. However, these four simple tones, the fun- 
damental and the three other partials mentioned, can be 
easily analyzed out of the compound tone.^ The untrained 
ear may have some difhculty at first in hearing all the par- 
tials mentioned, but a little practice will enable one to de- 
tect them. It should be noticed that the upper partials or 
overtones are always higher than the fundamental, and that 
they correspond to vibration rates which are simple multi- 
ples of the vibration rate of the fundamental. Thus, if the 
whole wire has a rate of 256 vibrations, the second partial is 
512 vs., twice the rate of the fundamental; the third partial 
is 768 vs., three times the fundamental; the fourth partial is 
1,024 vs., four times the fundamental. 

Timbre. — The character of compound tones, which is 
known as timbre, is due to the presence in them of the partial 
tones or overtones which we have just discussed. It is evi- 
dent that a given tone of the sam.e pitch and intensity sounds 
differently on different musical instruments. We can easily 
tell the difference between the same note on a piano and on a 
violin. This difference is due to the difference in timbre, 
and timbre is determined by the number and the intensity 
of the overtones present in the tones. The tones of different 
instruments vary in this respect. The flute has few and 
weak overtones. This gives its tone a dull character. In 
brass instruments the higher overtones predominate, giving 
a piercing quality to their tones. And so we find great variety 
in the character of the overtones in various musical instru- 
ments. Some may have the odd-numbered overtones and 



1 A simple way to isolate the partial tones is as follows: To isolate the 
second partial, strike the wire at Oxie-fourth its distance from one end to the 
other, then damp exactly in the middle by touching lightly with a piece of 
cotton; third partial, strike at one-sixth and damp at one-third; fourth partial, 
strike at one-eighth and damp at one-fourth. 



AUDITORY SENSATIONS 1 59 

some may have the even-numbered overtones; some may 
possess intense lower, others intense higher overtones. Of 
course, the noises which accompany the production of tones, 
Kke the plucking sound of the banjo or the scraping of the 
violin, may also aid one in detecting the difference in tones 
of different instruments, and have been considered by some 
authorities as contributing to differences in timbre. 

Beats. — If two c^ tuning forks, each of 256 vs., are set 
vibrating at the same time, the two tones will fuse together, 
giving a perfectly smooth, uniform tone. If, now, one of 
the forks is weighted with a bit of plastic clay or chewing- 
gum, its vibration frequency will be lessened and, conse- 
quently, its pitch slightly lowered. The two forks will, how- 
ever, give a single tone, but the intensity of the tone will 
rise and fall regularly. The points where the tone wanes in 
intensity are called heats. They are due to the interference 
of the sound-waves of the two tones. The waves of the 
slower fork lag behind the waves of the other fork more 
and more until a point is reached where the crest of the one 
and the trough of the other coincide. The waves then in- 
terfere or oppose each other and momentarily diminish the 
intensity of the combined tone. It is plain that the number 
of beats in a second will be equal to the difference between 
the vibration frequencies of the two forks. If the weighted 
fork is reduced to 255 vs., while the other remains at 256, 
there will be exactly one beat per second. By gradually 
increasing the weight upon the fork, the number of beats 
per second will be increased. As the beats become more 
rapid, the character of the tone changes. With 2 or 3 
beats a second the tone rises and falls gradually, at 8 per 
second the beats begin to strike more vigorously, while further 
increase up to 16 gives a ratthng character to the tone. At 
28 per second the tone is rough, harsh, and discordant; the 
maximum dissonance between the tones is reached at about 
this point. When the number of beats reach about 50 per 
second for this part of the scale, the dissonance disappears and 



l6o PSYCHOLOGY 

the two tones flow together smoothly again and manifest no 
disturbance. 

Careful observation shows that when the pitch of the 
lower tone becomes sufficiently different (about 8 vs.) from 
the other tone to be distinguished from it, an "intertone" 
appears, lying midway between the two generating tones. 
It is this tone which carries the beat. When the interval 
between the two generating tones reaches 40 vibrations, the 
intertone becomes inaudible and the two generating tones 
emerge and become distinguishable. 

Beats may be heard even when the tones are completely 
separated and conducted separately through sound-tight 
tubes, one to each ear. Since the sound-waves in this case 
are led to different end-organs, it was supposed by some 
that beats are of central origin, i. e., that they are produced 
in the cortical centres and not in the end-organs. But this 
theory is discredited by the fact that sound-waves in each 
ear can pass by bone conduction to the opposite ear. On 
account of this it is not possible to separate the two tones 
so far as the ears are concerned. 

Combination Tones. — If two tones that are not too similar 
in pitch are sounded together, there may be heard a third 
tone, much lower, sounding with them; and if the observa- 
tion is keen enough, a faint fourth tone may be heard, much 
higher than the two original tones. The lower extra tone 
is called a difference tone, and the higher extra tone a summa- 
tion tone. Both are known as combination tones. The differ- 
ence tone has a vibration rate equal to the difference in rate 
between the original tones, and the summation tone has a 
rate equal to the sum of the rates of the two original tones. 
If, for instance, we sound the tones d* (2,304 vs.) and g^ 
(1,536 vs.), the difference tone will be g'-^ (768 vs.), and the 
summation tone will be b^ (3,840 vs.).* The summation tone 

*The higher tones are preferable for demonstrating combination tones. 
Quincke's tubes d* and g^, when sounded together, bring out these tones fairly 
well. 



AUDITORY SENSATIONS l6l 

is very weak. Besides the difference tone mentioned, a sec- 
ond, third, and even a fourth difference tone has been de- 
tected. The cause of these combination tones is supposed 
to originate in the ear itself — eitherun the tympanic mem- 
brane or in the membrane covering the round window. It 
has been demonstrated that wh^n thin membranes are acted 
upon simultaneously by two sound-waves whose frequencies 
hold a certain relation to each other, other waves are prop- 
agated by the membranes. It seems necessary to explain 
combination tones in this way, for they have been demon- 
strated when no external air-vibrations corresponding to 
them were present. For this reason they have been called 
head-tones, because the vibrations causing them are generated 
within the head. 

Intensity. — The intensity of a sound-stimulus depends 
upon the amphtude of the sound-waves, and the intensity 
of the sensation increases with the intensity of the stimulus. 
The relation between the intensity of the stimulus and the 
intensity of the sensation was discussed under Weber's Law 
(seepage loi). Before a sound-stimulus can arouse a sensa- 
tion it must reach a certain degree of energy. In order to 
determine accurately the minimal or just-observable sound- 
stimulus, tests must be made in a sound-proof room, in order 
to eliminate all distracting sounds. There are, however, 
some individuals who can hear more distinctly when they 
are surrounded by a medley of sounds, such as the sounds of 
a noisy street, or shop, or in a room where a buzz of conver- 
sation is going on. Such individuals possess a blunted sensi- 
tivity to sound. It requires rather intense sound-stimuli to 
overcome the inertia of a sluggish auditory apparatus (in 
some cases, the ossicles of the middle ear). After the appa- 
ratus is once Hmbered up, it becomes more sensitive to sound- 
stimuli. 

Extensity. — ^In the case of cutaneous sensations, one and 
the same stimulus may act upon like end-organs, situated at 
different points p_ij the skin. In this case it arouses the same 



I 62 PSYCHOLOGY 

quality of sensation, which, however, may vary in space 
character. In hearing, however, this is probably not true. 
Here a single stimulus acts only upon a single auditory fibre, 
or the same band of fibres (Helmholtz theory). If this is 
true, a given tone-sensation cannot vary in extensity. The 
extensity of a given tone and its quality would never, for 
this reason, be separated in sensory experience. Tones do 
not, therefore, possess spatial arrangement or " alongsideness " 
among themselves. But they may possess extensity in the 
sense that we have used the word on a preceding page. The 
low. bass tones seem bigger — more massive — than the high 
tones of the treble. It has been suggested that the differ- 
ences in pitch are in themselves differences in extensity. 
This would apparently call for another theory for the physio- 
logical basis of hearing. In such a theory high tones would 
correspond to the stimulation of only a few cells or fibres, 
while the low or more massive tones would correspond to the 
stimulation of a larger number. 

Musical Tones, Consonance, and Dissonance. — If we com- 
pare the different tones in any tonal series, we shall find that 
those that are at certain intervals apart are psychologically 
more alike than others, i. e., that some pairs of tones fuse or 
blend much more completely than do other pairs. On the 
other hand, some tones stand alone and refuse to unite. 
The selection of tones for aesthetic purposes (music) was 
determined by this likeness and difference in the sensory 
character of tones. The musical scale is based primarily 
upon the fact that any tone whose vibration rate is double 
that of another will fuse readily with it, producing the maxi- 
mum degree of consonance, or union. This determines the 
octave. The keyboard of the grand piano has seven and a 
fraction octaves, ranging from A2 (26% vs.) to d' (4,096 vs.).^ 

' Th;se are the vibration frequencies adopted for scientific purposes. The 
German scale would read A2, equals 27^ vs. to c^, equals 4,224 vs. In this 
scale, middle c (c') equals 264 vs. On the English piano, middle c is 270 vs. 
While the absolute vibration frequencies may differ on diflfereut scales, the 
tonal intervals or tonal relations are always the same. 



AUDITORY SENSATIONS 1 63 

The octaves are as follows: 
Subcontra octave C2 = 16 vs. to Ci = 32 vs. 



Contra 

Great 

Small 

Once accented 

Twice 

Thrice 

Four times" 



. Ci = 32 vs. to Co = 64 vs. 

.Co = 64 vs. to c" = 128 vs. 

. c'' = 128 vs. to c'^ = 256 vs. 

. c^ = 256 vs. to c^ = 512 vs. 

. c^ = 512 vs. to c* = 1,024 vs. 

. c^ = 1,024 vs. to c* = 2,048 vs. 

. c^ = 2,048 vs. to c^ = 4,096 vs. 



To illustrate the tonal intervals within the octave, we 
may select the once-accented octave c' (middle c)-c^. The 
whole tones (diatonic scale) within the octave are: 



c' 


= 256 vs. 


dl 


= 288 vs. 


el 


= 320 vs. 


fi 


= 341-3 vs 


g^ 


= 384 vs. 


ai 


= 426.6 vs 


bi 


= 480 vs. 


c2 


= 512 vs. 



The intervals separating the successive notes of this scale 
may be expressed by the ratio of their vibration frequencies. 
The interval of c^ and d^ = 8 : 9; d^ and e^ = 9 : 10; e^ and f^ == 
15 : 16; fi and g^ = 8 : 9; g^ and a^ = 9 : 10; a^ and b^ = 8 : 9; 
b^ and c^ = 15 : 16. The interval of c^ and g^ = 2 : 3 (c^ = 
256 vs., gi = 384 vs.; 256 : 384 = 2:3). As has been said, 
the most perfect consonance of all the possible intervals is 
that of c^ and c^ = i : 2. Within the octave, other intervals 
may be selected, giving decreasing degrees of consonance, 
some intervals producing a decided dissonance. If we ar- 
range the intervals in their order of consonance or tonal like- 
ness, starting with c\ we have: 

c^ and c- =1:2 (octave), 
c^ and gi = 2 : 3 (fifth). 
c^ and P =3:4 (fourth) . 
c^ and e^ =4:5 (major third). 
c^ and a^ =3:5 (major sixth). 



164 PSYCHOLOGY 

These are the pleasing or consonant intervals within the 
octave: On the other hand, the interval of c^ and d^ =^ 8:9, 
major second; and c^ and b^ = 8:15, major seventh, are de- 
cidedly dissonant and displeasing. In the simple diatonic 
scale any two tones whose vibration frequencies stand to each 
other as I : 2 (octave) ,2:3 (fifth) ,3:4 (fourth) ,4:5 (major 
third), or 3 : 5 (major sixth) will, when sounded together, 
blend without roughness or dissonance. If, however, we 
should start with any other tone (tonic), say d^, and calcu- 
late the vibration frequencies of the tones that lie a fifth, a 
fourth, a major third, a major sixth, etc., above d\ there 
would not be a sufficient number of tones in the diatonic 
scale to construct these intervals. So it was necessary, in 
order to maintain these relations between the tones, to insert 
other tones within the octave. But such a large number of 
new tones is required to make the intervals exact that it 
makes the octave unwieldy. In overcoming this difficulty, a 
compromise was made by inserting five half-tones for the 
pianoforte and other similarly tuned instruments, so that 
the octave contains twelve tones, equally distant from each 
other. This is the equally tempered scale, which is now in use 
in this country and Europe. The only exactly tuned interval 
in the equally tempered scale is the octave; all the others are 
slightly out of tune. The approximation to the true intervals 
is so close, however, that for all but the most sensitive and 
highly trained ears the result is satisfactory. 

Consonance and dissonance have been explained in several 
ways. According to Stumpf,^ consonance is due to the fusion 
of tones. Those tones that blend smoothly and fuse with 
one another more or less completely, so that the resulting 
sensory experience resembles a single tone sensation, are con- 
sonant; while those tones that refuse to blend or fuse together 
into a single experience and remain apart, are dissonant. 
Unity of tonal impression is, therefore, according to Stumpf, 

' "Konsonanz und Dissonanz," Beitrdge zur Akustik und Musikwisscnschaft, 
1898, I, I. 



AUDITORY SENSATIONS 1 65 

the measure of consonance. Helmholtz considers consonance 
the absence, and dissonance the presence of beats in simul- 
taneously sounding tones. In considering this theory, we 
must remember that most single tones are compounds, made 
up of fundamentals and overtones. The overtones of one 
note may coincide or may beat with the overtones of another 
note. The degree of consonance of tones goes hand in hand 
with the amount of coincidence of their overtones. In the 
octave, where there is perfect consonance, the overtones co- 
incide and, therefore, there is no beating. In the minor sixth 
(c — Fa = 5:8), just on the border-line between consonance 
and dissonance, the lower overtones (the second of c and the 
first of 7a) beat audibly with each other. In more dissonant 
intervals the overtones beat still more markedly. The rough- 
ness of dissonant intervals, produced by the beats, is unpleas- 
ant, just as intermittent sensations of any kind are unpleasant. 
In regard to successive tones, Helmholtz has suggested 
that their relation depends upon the similarity or dissimilarity 
of their overtones. A tone is most like its octave tone be- 
cause the overtones of the two are coincident. In passing 
from the one to the other a large part of the end-organs 
active for the first tone are stimulated again by the second. 
A tone and its second or its seventh show little, or no, kin- 
ship, because the overtones of the one are different from 
those of the other. In passing from the one to the other of 
such tones, different end-organs are stimulated. Therefore 
the tones have nothing in common. 



CHAPTER VIII 

VISUAL SENSATIONS 

The eye furnishes us by far the greatest number and 
variety of sensory experiences of all the sense-organs. The 
sensitive end-organs which give these visual sensations are 
the rods and cones of the retina. The eyeball with all its 
parts acts as a camera obscura to bring the rays of light from 
outer objects to a focus upon the sensitive end-organs. It 
has three coverings: (i) The sclera, an outer protective coat, 
extending into and forming the transparent cornea in front; 
(2) the choroid, the color coat, whose dark pigment excludes 
all the light from the inner chamber, except that which 
enters through the pupil, a round adjustable opening in the 
choroid; and (3) the retina, the thin inner lining of the eye- 
ball, containing the sensitive rods and cones connected with 
the fibres of the optic nerve, which are distributed here for 
the purpose of transmitting impulses to the brain. The re- 
fractive media of the eye are: (i) The cornea, the transparent 
covering in front; (2) the aqueous humor, a lymph-like fluid 
filling the anterior chamber of the eyeball; (3) the crystalline 
lens, a clear, transparent body, biconvex in shape, enclosed 
in a thin, elastic capsule and attached to the suspensory liga- 
ment; and (4) the vitreous humor, a jelly-like body filhng the 
back part of the eyeball. These media are sufficient when 
the eye is at rest to bring the parallel rays from objects more 
than 20 to 30 feet distant to a focus on the retina. For 
nearer objects the crystalline lens changes its curvature to 
suit the distance, becoming more and more convex as objects 
approach and less convex as objects recede from the eye. 
This adjustment of the lens for near and far objects is termed 
accommodation. 

166 



VISUAL SENSATIONS 



167 



Accommodation for near objects is brought about by the 
action of the cihary muscle, which by contracting lessens the 
strain of the suspensory ligament on the lens and allows it 



Ciliary 
Body 



Posterior 
Chamber 



Conjunctiva 




X-Optic Nerve 



Fig. 53. — Horizontal section through the left eye. 



by its own elasticity to become more convex. For far ob- 
jects the ciliary muscle relaxes, allowing the eyeball to bulge 
outward, and so by pulling on the suspensory ligament flat- 
tens the lens. 

By means of six muscles attached to the external coat of 



1 68 PSYCHOLOGY 

the eyeball the eyes are revolved in their sockets so that 
they may be directed in different directions. For far objects 
the lines of sight for the two eyes are practically parallel, 
but for near objects they converge. In looking from a near 
object to one farther away, the lines of sight diverge, i. e., be- 
come less convergent. These acts of adjustment are known 
as convergence and divergence. The acts of convergence, diver- 
gence, and accommodation take place reflexly. 

The Retina. — The thin, transparent retina extends for- 
ward almost to the ciliary process, so that it covers all the 
inner surface of the eyeball, upon which images of objects 
can fall. There are many different layers or differentiated 
structures in the retina, which the microscope is able to 
reveal. Of these the rods and cones are of most interest to 
us because they are the end-organs which receive the light- 
stimuli and generate the nervous impulses which are sent to 
the brain centres, resulting in sensations of light and color. 
The rods and cones are turned away from the source of light, 
making it necessary for the light-rays to penetrate all the 
layers of the retina before falling upon them. Under certain 
conditions the shadows cast by the blood-vessels in the inner 
layer of the retina can be seen, showing that the part of the 
retina which receives impressions lies on the side of the retina 
away from the source of light and back of the retinal blood- 
vessels. If, in a lighted room, a candle is held close but to 
one side of the eye, and if while one is peering into the dark- 
ness the candle is moved slightly but rapidly to and fro, a 
network of dark branching lines will be seen. This is known 
as Purkinje^s network. 

In the centre of each retina, directly opposite the pupil, 
there is a small yellow spot {macula lutea), within which is 
found a pit- like depression called t\iQ fovea centralis. Here the 
cones are directly exposed to light-rays because the inner 
layers and blood-vessels are pushed aside to form the pit of 
the fovea. It is upon the fovea that the images of objects 
are focussed in direct vision. The fovea is the most sensitive 



VISUAL SENSATIONS 



169 



part of the retina, and therefore gives the most distinct 
vision. In looking at an object we reflexly turn the eyes 
so that its hght-rays fall upon the fovea. 

The distribution of the 
rods and cones in the ( 
retina is not uniform. 
There are no rods in the 
fovea centralis. Only 
cones are found there. 
They decrease in num- 
ber, however, as we pass 
toward the periphery of 
the retina, where the rods 
greatly predominate. 
Movement of objects is 
sensed more quickly by 
the outer parts of the 
retina, while accurate 
vision is best at the fo- 
vea. The fact that the 
periphery of the eye is 
most sensitive to move- 
ment probably has^a bio- 
logical significance. Sen- 
sitiveness to the approach 
of danger from behind or 
from the sides gave or- 
ganisms a great advan- 
tage in their ability to 
survive. Man has evi- 
dently shared in this 

sensitiveness to movement in indirect vision. The periphery 
of the retina is less sensitive to color; in fact, the extreme 
outer portion is color-blind. 

The optic nerve enters each eyeball on the nasal side of 
and at a point not far from the fovea centralis. At its point 




Fig. 54. — Diagrammatic section of the 
retina. (After Greefl). I, Pigment epi- 
thelium; IT, rods and cones. Outside 
the fovea the rods and cones are both 
found, in the fovea only con£s. Ill, 
IV, V, VI, VII, show intermediate 
neurones and nerve connections. From 
the neurones at VIII the optic fibres 
pass out as indicated at IX toward the 
optic disc where they leave the eyeball 
to form the optic nerve; X limiting 
membrane of retina. A ray of light 
entering the eye passes through the 
retina from X to II. 



lyo PSYCHOLOGY 

of entry, known as the optic disc, there are no rods and 
cones; consequently, no vision is possible there. For that 
reason the optic disc is commonly known as the blind spot. 



+ 



Fig. 55. — Close the left eye. Fixate the cross in the figure. When the book 
is a little over eight inches from the eye, the dot will disappear. Slowly 
move the book farther away until the square disappears. The eye must be 
steadily fixed upon the cross. The explanation of the inability to see the 
figures is, of course, found in the fact that they fall upon the blind spot. 
(From Thorndike's " Elements of Psychology.") 




+ 




Fig. 56. — Notice that when the white disc in the black square falls upon the 
blind spot it is filled in with the black of its surrounding background. In 
order to project the disc upon the blind spot, close the left eye and fixate 
the cross with the right eye. The book should be held about eight inches 
from the eyes with the cross directly in front of the right eye. 

(From Thorndike's " Elements of Psychology.") 



The iris of the eye functions in the same way as the dia- 
phragm of a camera. By contracting and expanding it varies 
the size of the pupil, thus controlling the amount of light 
entering the eye. If too much light enters, the pupil becomes 
smaller; if not enough, it becomes larger. This action of the 



VISUAL SENSATIONS 



171 



iris is a pure physiological reflex, known as the pupillary 
reflex. It is set off by the action of light upon the eye. 

The power of the resting eye, as an optical instrument, 
is such that parallel rays (rays from distant objects) are 
brought to a focus upon the retina. In order to form clear 
images of nearer objects whose rays are divergent, the cur- 
vature of the lens must be changed by the act of accommoda- 




FiG. 57.— The change of the lens in accommodation. (From Ladd and Wood- 
worth, after Helmholtz.) The left half of the figure shows the lens focussed 
on a distant object, the right half on a very near object, c, the ciliary 
muscle; s, the suspensory ligament. 



lion. In this case the front surface of the lens bulges for- 
ward, making the lens more convex, thus increasing its focal 
power. This is illustrated in the accompanying cut. 

The limits of accommodation vary with the condition of 
the eyes and with age. The young, elastic lens can accom- 
modate for a distance of about 7 to 10 cm. In presbyopia, 
inelasticity of the lens attendant upon old age, the near limit 
of accommodation may be increased to 50 or 60 cm. This 
limit may be determined very roughly by closing one eye 
and holding up a pin before the other eye, and after getting 
a clear image moving it toward the eye until the image begins 
to blur. The lens is not able to bring the light-rays to a 
sharp focus upon the retina nearer than this point. 

If the eyeball, from the retina to the lens, is too long, or 
if the refractive surfaces of the lens or cornea^ are too great 

* The cornea also acts as a refractive medium. 



172 PSYCHOLOGY 

in curvature, the rays from distant objects are brought to a 
focus in front of the retina and are diverging when they 
reach it, blurring the image. Only near objects can be seen 
clearly. This condition is called myopia, or near-sightedness. 
Concave glasses will correct the difficulty. If, on the other 
hand, the eyeball is too short, or the curvature of the lens 
and cornea is not great enough, light-rays are brought to a 
focus back of the retina. This is called hyperopia, or far- 
sightedness. By wearing convex glasses the light-rays are 
brought to a focus at the retina. Another condition, known 
as astigmatism, is caused when the refractive surfaces (usually 
the cornea) are not perfectly curved. When this is the case 
the rays from one part of an object may be properly formed 
on the retina, while other rays are not, resulting in a badly 
focussed image and constant eye-strain. 

The image of an object upon the retina is upside down. 
The fact that we see the object right side up, although its 
retinal image is upside down, offers no difficulty when we 
consider that we are not conscious of the retinal image itself. 
The spatial relations of up and down, right and left, are a 
matter of association entirely. We perceive as "up" that 
part of an object to which the hand must be raised in touch- 
ing or grasping it. 

The Optic Nerve and Optic Centres. — The nerve-fibres 
from all parts of the retina are brought together at the optic 
disc and there leave the eyeball as the optic nerve. The 
nerves, one from each eye, pass backward and, joining to- 
gether, form the optic chiasma, or optic commissure. Here 
each nerve divides, one half going to the right brain and the 
other going to the left brain. Part of the fibres from each 
retina, those from the outer or temporal halves, pass to the 
same sides of the brain, while the other fibres, those from 
the inner or nasal halves of the retinae, cross over in the 
chiasma and pass to the opposite sides of the brain. Accord- 
ing to this arrangement, the fibres from the temporal half of 
the right eye and the nasal half of the left eye go to the right 



.T.F. 



R.N.F. 




L.O.S. L.O.D. 



Fig. 58. — Scheme of the mechanism of vision. (James after Seguin.) The 
cuneus convokition {Cu.) of the right occipital lobe is supposed to be injured, 
and all the parts which lead to it are darkly shaded to show that they fail 
to exert their function. F.O. are the intra-hemispheric optical fibres. P.O.C. 
is the region of the lower optic centres (corpora geniculata and quadrige- 
mina). T.O.D. is the right optic tract; C, the chiasma; F.L.D. are the 
fibres going to the lateral or temporal half T. of the right retina, and F.C.S. 
are those going to the central or nasal half of the left retina. O.D. is the 
right, and O.S. the left, eyeball. The rightward half of each is therefore 
blind; in other words, the right nasal field, R.N.F., and the left temporal 
field, L.T.F., have become invisible to the subject with the lesion at Cu. 
(From Angell's " Psychology.") 



174 PSYCHOLOGY 

brain, while the fibres from the temporal half of the left eye 
and the nasal half of the right eye go to the left brain. Ac- 
cordingly, light-stimuli from objects on the left side of the 
body (falling upon the right half of each retina) send their 
impressions to the right brain, while impressions from objects 
on the right side of the body go to the left brain. After 
leaving the optic chiasma the nerve-fibres go to the mid- 
brain, where they terminate in the optic thalami, external 
geniculate bodies and the superior quadrigemina. There 
they make connections with another set of fibres, which pass 
to the cuneus convolutions of the occipital lobes, which con- 
stitute the cortical centres for vision. The right occipital 
cortex contains, then, the centre for the right halves of the 
retinae, while the left occipital lobes contain the centre for 
the left halves of the retinas. 

If one of the optic nerves should be cut, complete 
blindness of the corresponding eye would result. But if 
one of the optic tracts should be cut it would cause blind- 
ness in one half of each eye, or hemianopsia, as it is called. 
A lesion in one of the occipital lobes may also cause hemia- 
nopsia. 

From this brief description of the eye and its connections 
with the brain, we see that it is a wonderfully arranged pho- 
tographic instrument whose many parts all conspire to the 
one end of producing a clear image of outer objects upon the 
sensitive retina. It is very evident that the image itself is 
not sent to the brain. Some physiological process in the end- 
organs must intervene between the image and the impulses 
which go to the cortical centres. Just what that process is, 
is a matter of conjecture, as we shall see when we take up 
the color theories. It has long been supposed that it is 
chemical in nature. So, when it was discovered that the 
outer ends of the rods became strongly tinged with a purple 
substance when light was excluded from the eye, and that 
this substance, known as visual purple, bleached very rapidly 
when exposed to light, and regained its purplish-red color 



VISUAL SENSATIONS 1 75 

again whenever light was withdrawn from it, it was thought 
that the true visual process had been discovered. Another 
fact appeared to fortify this supposition, namely, that some 
of the colored light-rays bleach this visual purple more rap- 
idly than others. This would seem to provide a physiologi- 
cal basis for the qualitative differences in colors. But the 
fact that visual purple is not found on the fovea, the area of 
clearest vision and, moreover, that vision is not diminished 
after the visual purple is exhausted, make it highly improb- 
able that the activity of the visual purple is the real visual 
process. However, a number of facts indicate that the visual 
purple increases the sensitivity of the eye in very dim illu- 
mination, i. e., in twilight vision. It is a very common ob- 
servation that when we pass from a very light room into the 
dim illumination of the night, at first we are unable to see at 
all. But gradually the eye adapts itself to the darkness, so 
that we can see well enough to get about. Or, when passing 
from the dark into a lighted room, the light is at first so bril- 
liant that a short period of light-adaptation is necessary be- 
fore the eye can react properly. It is quite probable that 
the building up of the visual purple on the rods in the dark 
makes them more sensitive to dim light, and that by its 
means the eye becomes "dark-adapted." It is known that 
the visual purple builds up more slowly than it bleaches out, 
which is in agreement with the fact that the eye adapts itself 
more slowly to the dark than to the light. Still another in- 
teresting fact to be considered in this connection is that the 
fovea, which contains only cones and no visual purple, is 
practically bhnd in very dim light. All this makes it very 
probable that the function of the purple is to increase the 
sensitivity of the rods to dim light. The eyes of bats and 
other nocturnal animals have practically no cones, but the 
rods, which are present in great numbers, are liberally sup- 
plied with visual purple. 

It seems, therefore, that the rods and cones of the eye 
perform different functions: the rods for twilight and the 



176 PSYCHOLOGY 

cones for daylight vision. The rods give sensations of light 
when the illumination is too low to stimulate the cones to 
activity. It is also probable that the rods furnish us with 
sensations of brightness or colorless light only, and that the 
cones furnish us with our color-sensations in addition to sen- 
sations of brightness of moderate intensity. In very dim 
light (deep twihght), when the fovea is blind, no color can 
be seen. All colors then appear as gray. The sensitivity of 
the eye to color is greatest at the fovea, and decreases as the 
cones decrease in number toward the periphery, where the 
eye is absolutely color-blind. There are other facts which 
point in the same direction, but these are sufficient to indi- 
cate a differentiation of the rods and cones with regard to 
light-sensations. 

Stimulus. — The adequate stimulus for visual sensations is 
the vibrations of ether, which is supposed to be the medium 
by means of which light is transmitted. The eye may be 
stimulated inadequately by purely mechanical and electrical 
energy. A blow on the head may cause us to see stars, or 
fill the field of vision with sudden light. By pressing upon 
the outer surface of the closed eye, phosphenes, or circles of 
light, may be seen in the inner field of vision. An electric 
current will also arouse sensations of light when passed 
through the eyes. The physiological processes which are 
going on in the retina itself also act as a stimulus. On clos- 
ing the eyes and covering them to exclude all external light, 
we find that instead of absolute darkness the eye is dimly 
illuminated with its own light (Eigenlicht), giving an ever- 
changing cloud effect. 

But, as we have said, the normal stimulus is the wave 
movement, or vibrations of ether. The eye is sensitive only 
to the ether-vibrations which lie between the infra-red and 
the ultra-violet vibrations. Ether-rays below the red and 
above the violet arouse no visual sensations, although they 
are known to exist. The light-rays that stimulate the eye 



VISUAL SENSATIONS 177 

are all contained in the spectrum, whose vibration rates are 
approximately as follows: 

Fraunhofer line B, Red, 450 trillion vibrations per second 

" " C, Orange, 472 " 

" D, Yellow, 526 " 

" " E, Green, 589 " 

" " F, Blue-green, 640 " 

" " G, Blue, 722 " 

" " £r, Violet, 790 " 

By inspecting the colors of the spectrum the student will 
see that each color is spread out in a narrow band. A single 
vibration rate cannot, therefore, adequately represent a color, 
for any color may have a number of different vibration rates. 
For instance, red is practically the same in appearance from 
440 trillion to 460 trillion vibrations. 

The red rays, the slowest in vibration rates, are the long- 
est waves, while the more rapid violet waves are the shortest 
in length. The waves vary in length from red, 0.000687 mm., 
to violet, 0.000393 mm. 

Thus we see that the quality (hue) of sensations of color 
depends upon the wave-lengths, or the vibration frequencies 
of light. For example, vibration frequencies ranging around 
450 trillion per second give the sensation of red, while those 
of 589 trillion give green. But the correspondence of change 
of vibration rate and change of hue is not uniform in all 
parts of the spectrum. At the lower end considerable change 
in the number of vibrations is required to cause a change 
in the quality of red. Green, on the other hand, changes its 
quality very rapidly, corresponding to a smaller change in 
the vibration rate of the stimulus. 

When homogeneous light-rays (light-rays of the same 
length, or of the same vibration frequency) fall upon the 
cones, the resulting sensation is a pure color. But if the 
light-rays of all the differing frequencies are mixed, the result- 
ing sensation is white. We may say in general that for nor- 



lyS PSYCHOLOGY 

mal daylight vision homogeneous or pure light-rays are the 
stimuli for the pure color-sensations ; while a mixture of all the 
light-rays is the stimulus for the achromatic or colorless sen- 
sations.^ 

The colorless, white light of sunlight is a mixture of all 
the light-rays. When a beam of colorless light is passed 
through a prism, its different rays are bent at slightly differ- 
ing angles, thus splitting up the complex white light into its 
constituent elements and forming the spectrum. 

Kinds of Visual Sensations. — Visual sensations fall into 
two general groups: (i) The achromatic and (2) the chromatic. 
The achromatic or colorless sensations form a series from 
white through gray to black. Although there is a difference 
of opinion on the subject among psychologists, we shall con- 
sider white and black as different qualities of colorless sensa- 
tions, and gray as a compound of white and black. The 
achromatic sensations, however, have but one stimulus (col- 
orless light), which exists in various degrees of intensity. 
Black is the result of a very low degree, gray of a medium 
degree, and white of a very high degree of intensity of color- 
less light. It has been suggested that black is the absence of 
light-stimulation (the resting condition of the retina), and 
therefore corresponds to inactive brain centres, or at least 
brain centres which are receiving no nervous impulses from 
the retina. This negative conception seems unjustifiable. 
Every sensation is the result of stimulation of some end- 
organ and is, therefore, a positive experience. Even when 
we first enter the blackness of an absolutely light-proof dark 
room, where no external stimulus can reach the eye, the 
physiological processes of the retina itself cause minimal sen- 
sations of light, ordinarily considered as black. As soon as 
the eye becomes dark-adapted, the black becomes lighter. 
The ordinary blacks which we see in the outer world are 
certainly the results of stimulation of the retina. The nega- 
tive conception would make "seeing black" equivalent to 

1 Certain modifications will be made to this general statement later. 



VISUAL SENSATIONS 1 79 

seeing nothing at all (blindness). However, "seeing black" 
is quite different from "being blind." An object may trans- 
mit a considerable amount of light to the eye and yet appear 
black. Moreover, there is not a single black, but many dif- 
ferent blacks, as he who has been commissioned to match a 
given black fabric at the dress-goods counter well knows. 

Besides the usual method of arousing sensations of the 
white-gray-black series, namely, stimulation by light-rays of 
all wave-lengths acting simultaneously upon the retina, there 
are several other means of arousing them: Any two comple- 
mentary colors when mixed will produce gray; very small 
areas of colors, or any color in very faint Hght, or color fall- 
ing on the periphery of the eye will be seen as gray. 

The chromatic sensations, or sensations of color, form a 
very large group of sensory experiences, not only the experi- 
ences of the colors of the spectrum, but also the thousands 
of tints, shades, and mixtures, which are derived from them. 
The spectral colors themselves, or rather the sensations which 
we get from them, are not all elementary. Considering the 
colors of the spectrum, beginning at the lower end, we have 
red, orange, yellow, green, blue, indigo-blue, and violet. It 
is evident that orange partakes of the qualities of red and 
yellow, and that indigo-blue and violet are mixtures of blue 
and red. This leaves red, yellow, green, and blue as the ele- 
mentary sensations of color. Each one of these four colors 
possesses a color quality totally different from the others, and 
each quality is simple and unanalyzable. There are, then, 
Just four kinds of color-sensations — red, yellow, green, and 
blue. All others are compounds, formed out of the elemen- 
tary sensations. This classification, being purely psychologi- 
cal, does not in any way conflict with the classifications of 
the colors made for other purposes.^ 

^ The artist classifies colors into three primary colors — red, yellow, and 
blue. The physicist also reduces colors to three — red, green, and blue-violet, 
which he names fundamental colors. The physiologist speaks of four colors 
(purple-red, bluish green, blue, and yellow) as invariable or staple colors. 



l8o PSYCHOLOGY 

Brightness of Colors. — The spectral colors are not all of 
equal brightness. In ordinary daylight illumination, yellow 
is the brightest and violet the darkest color, i. e., yellow is 
nearest and violet farthest away from white. Since the grays 
form a series of increasing brightness from black to white, it 
is possible to match the brightness of any one of the colors 
with some degree of gray. In this way we can determine 
the brightness of the colors. We shall find that yellow will 
correspond in brightness to a gray which stands higher up 
(nearer white) than the gray which corresponds with any of 
the other colors. Violet corresponds with a gray lower down, 
i. e., farther away from white. (See the color pyramid, 
Figure 59.) Now, if the illumination of the spectrum is in- 
creased in intensity, all sensations of color tend to disappear 
and the spectrum appears washed out or whitish, and at 
the maximum intensity all colors become white. Yellow 
and blue hold their colors longest. If, on the other hand, the 
illumination (brightness) of the colors is reduced, the colors 
become darkened and finally change into colorless lights of 
low intensity.^ In general, then, we may say that when 
color-stimuli become sufficiently intense, the colors are seen 
as white; if they become sufficiently feeble, colors are seen as 
dark gray or black. 

Purkinje Phenomenon. — An interesting fact, known as 
Purkinje's phenomenon, may be observed when the eye be- 
comes dark-adapted and the illumination of the spectral 
colors reduced to a minimum. In ordinary light, when the 
eye is light-adapted, the brightest color in the spectrum is 
yellow, but when the illumination is very dim and the eye 
becomes dark-adapted, the region of maximum brightness 
changes from the yellow to the green. The reds become rela- 
tively darker, while the blues become brighter. This change 
of brightness takes place only when the eye becomes dark- 
adapted, and consequently it does not occur in foveal vision. 
The Purkinje phenomenon, therefore, appears only when the 

' Red appears to hold some of its color until it disappears altogether. 



VISUAL SENSATIONS l8l 

eyes shift from daylight to twihght vision, and become dark- 
adapted. 

It is interesting to note in this connection that when a 
dark-adapted eye is exposed to different colored lights, the 
visual purple is bleached most rapidly by green light, next 
by blue light, and least of all by red light. This may explain 
the relative degrees of brightness of these colors in a dark- 
adapted eye. 

Saturation. — It is quite- evident that there is considerable 
variation, in each of the four kinds of color-sensations. For 
instance, there are many colors which we may call red^ many 
that may be called blue, etc., but the purest red, the saturated 
red, is found in the spectrum. Likewise, all the other colors 
are purest or most saturated in the spectrum. Saturation 
refers to the degree of purity of a color, its freedom from ad- 
mixture with other light-waves. So a color is said to be 
saturated when it contains little white light — when it is as 
little like white as possible. We never experience absolutely 
pure or completely saturated colors. There is always some 
white light in any color, but those of the spectrum are the 
nearest approach to saturation. Of these, red and blue are 
most, while yellow and green are the least, saturated. 

Complementary Colors. — If we examine the spectrum, we 
find that adjacent colors shade off into each other gradually; 
red shades into yellow through orange, yellow passes into 
green through greenish yellow and yellowish green, green into 
blue through bluish green and greenish blue, and blue passes 
back to red through the violets, so that the colors, instead of 
forming a straight line, may be arranged in a circle, or rather 
as a square, since the color quality changes abruptly four 
times in making the circuit from red back to red again. 
Now, between any two adjacent colors lie mixtures of the 
two colors, which possess the color qualities of both. If, 
however, we select pairs of colors not adjacent to each other, 
such as yellow and blue, there is no way of passing from one 
to the other through intermediate colors. When we mix 



I»2 



PSYCHOLOGY 



such pairs of colors, instead of giving a spectral color of 
intermediate hue, they tend to neutralize each other and 
produce a gray. Such colors are said to be complementary 
colors. Complementary colors are those colors which, when 

mixed, give gray. Thus yellow and 
blue are complementary colors. 
Some of the other pairs of comple- 
mentary colors are red and bluish 
green, orange and greenish blue, 
green and reddish purple. 

The Color Pyramid. — A simple 
scheme for representing the rela- 
tions of color-sensations to each 
other and to the white-gray-black 
series can be made by arranging 
the colors in the form of a double 
pyramid, and placing the grays 
along the axis connecting the two 
poles. 

This double pyramid represents 
the two systems of sensations — sen- 
sations of light and sensations of 
color. Around the base (or, rather, 
where the bases join) we may ar- 
range the saturated colors in the 
In fact, we may consider the straight 
line of the spectrum bent in four places (in the red, the 
yellow, the green, and the blue), to form a square. We 
may add purple to make the connection between violet 
and red. Along this line lie all the spectral or saturated 
colors. Orange lies between red and yellow, yellow-green 
between yellow and green, blue-green between green and 
blue, and violet and purple between blue and red. The 
eye can detect from 150 to 160 different spectral colors. 
The white-gray-black series is arranged along the straight 
line joining the upper apex with the lower, white at the top 




Fig. 59. — The color pyramid. 

(From Titchener's ' ' Text-book of 
Psychology.") 



order of the spectrum. 



VISUAL SENSATIONS 1 83 

and black at the bottom, with all the intermediate grays 
between. There are about 700 different degrees of gray, from 
the whitest white to the darkest black. The middle gray is 
at the point where the line joins the base. Along the lines 
from the corners of the base to the upper apex lie all the 
tints of the colors, from middle brightness to white, while 
along the lines from the corners to the lower apex lie all the 
shades between the colors and black. For instance, between 
blue and white there is a series of tints of blue, which start 
with blue of middle brightness and gradually fade out into 
white. Likewise, between the blue and black is another 
series, which we may arbitrarily name "shades,"^ beginning 
with blue and ending with black. So with all the other 
colors represented on the base of the double pyramid. If, 
now, one pass from a saturated color on the outer rim of the 
base toward the centre of the pyramid, another series of 
colors, becoming less and less saturated and ending at the 
centre in neutral or middle gray, is represented. 

The results of mixing colors are roughly indicated in the 
pyramid. Mixtures of any two colors He on the straight 
lines between the colors mixed. If red and yellow are mixed 
the result is an orange, which is found on the line in the 
pyramid between the two colors. A mixture of white and 
black gives a middle gray. If two complementary colors, 
say yellow and blue, are mixed, the result, gray, is likewise 
found on an imaginary line joining the colors in the pyramid. 

The difference in the brightness of the spectral colors is 
represented by the angle which the base makes with the 
white-gray-black line. Yellow, being the brightest color, is, 
therefore, found nearest white and corresponds in brightness 
to the gray represented directly opposite on the dotted line. 
Blue, having a lower degree of brightness, is farther away 
from white, and is, therefore, matched with a gray lower 
down on the dotted line. 

^ The use of the word "shade" in this restricted meaning is purely arbitrary 
and technical, 



184 PSYCHOLOGY 

The number of different sensations of light and color, 
tints and shades, and their mixtures, which the eye can see 
and which must be represented upon the surfaces and in the 
volume of the color pyramid, is very large. It has been 
variously estimated from 33,000 upward. 

Color Mixtures. — By superimposing two different colored 
lights upon the same retinal surface we get a mixture of 
the two colors. The simplest way to mix colors is to place 
them on a cardboard disc, which can be made to revolve 
very rapidly on a color- wheel. In this way a disk having two 
or more different colors will, when revolved rapidly enough, 
give a smooth, even color, which is the mixture of the given 
colors. For instance, if a disc having all the colors on it is 
revolved, the result is an even neutral gray. If a disc is 
half red and half yellow, the mixture will be orange; if half 
yellow and half blue, the mixture will be a gray, and so on. 
Thousands of mixtures of saturated colors, tints, and shades 
with each other and with the whites, grays, and blacks may 
be made in this way. The most important principles of 
color-mixing are as follows: (i) When complementary colors 
are mixed in the proper proportion the result is a gray; if 
not in that proportion, they will give a washed-out or un- 
saturated color of the same quality as the preponderating 
color. Thus, if a large part of the disc is blue and only a 
small part yellow, the mixture will be an unsaturated blue. 
(2) When colors that are not complementary are mixed, the 
result is an intermediate color. The hue will vary with the 
relative amounts of the two colors. If blue and green are 
mixed, the result is an intermediate blue-green; if the rela- 
tive amount of green is large, the mixture will be a green 
tinged with blue; if, on the other hand, blue forms the larger 
part, then the mixture will be blue tinged with green. 

Light and Color Adaptation. — The quality of a light or 
color sensation is modified by the length of time the stimulus 
has acted upon the retina. This is due to the adaptation of 
the end-organs to the stimulus. When dark glasses are first 



VISUAL SENSATIONS 185 

put on, everything appears dark, but after a time the dark- 
ness wears off. Likewise, when colored glasses are placed 
before the eyes, their color is strongly marked, but later it 
niay disappear altogether and objects will appear in their 
normal colors. The change which a color undergoes as the 
stimulus continues may be observed. Look steadily at a 
saturated red with one eye, while the other is closed. After 
one minute compare the red seen by the adapted eye with 
the same red seen by the non-adapted eye. The red of the 
adapted eye appears much less saturated than that of the 
non-adapted eye. If color-stimuli act on the retina for a 
long period, they become less and less able to arouse color- 
sensations. Brightness-stimuli also become less and less able 
to arouse their original sensations as they continue to act. 
In general, we may say that, as the process of adaptation 
continues, all sensations of brightness and color tend more 
and more toward their opposites. If we gaze at a white 
cardboard it becomes darker; if we gaze at black it becomes 
lighter. So with colors; they tend to lose their saturation 
as the stimulus continues. 

The effect of adaptation to any light and color stimulus 
not only blunts the sensitivity for the given stimulus, but it 
also increases the sensitivity of the retina for the opposite or 
complementary color. When we go from the yellow lamp- 
light of a closed room into the daylight, everything looks 
bluish. Gaze steadily at a sheet of yellow paper for thirty 
seconds, then at a neutral gray surface, and observe that the 
gray is -tinged with blue. After adaptation to any color, a 
neutral gray will appear to possess the tint of the comple- 
mentary color. It seems, then, that any light or color stim- 
ulus sets up not only its own retinal process, but tends also 
to set up the opposite process. This tendency shows itself 
in the negative after-images, or after-sensations, of light and 
color. If we fixate a small blue square for a short time and 
then look at an even gray surface, the after-image of the 
square will appear in a yellowish tint. The negative after- 



1 86 PSYCHOLOGY 

image of a window filled with sunlight is just the opposite 
of the original sensations in distribution of light and dark 
parts; the panes appear dark and the sashes light. Negative 
after-images of color and brightness are the opposites of the 
original sensations. The after-effect of adaptation is always 
in the opposite direction. 

Successive Contrasts. — The tendency of visual stimuli to 
set up opposite sensory processes is responsible for the so- 
called successive contrast effects. After adaptation to white, 
a dark gray appears darker; after becoming accustomed to 
yellow, blue appears bluer; and so on. That is, after white, 
gray is darker, and after yellow, blue is bluer "by contrast," 
as we commonly say. 

Simultaneous Contrasts. — In successive contrasts, the ef- 
fects are wrought upon the same retinal areas. But in simul- 
taneous contrasts, different areas of the retina are concerned. 
The stimulation of one part of the retina affects or modifies 
the action of other parts. Here, as in adaptation, the con- 
trast effect is in the opposite direction. For instance, a small 
gray square surrounded by a colored field always appears 
tinged with the color complementary to the surrounding color. 
A gray surrounded by a bluish green becomes markedly red- 
dish by contrast. The blue-green sets up the complemen- 
tary color process in the part of the retina stimulated by the 
gray. It has been suggested that the bluish-green photo- 
chemical activity of the surrounding retinal field draws from 
the gray retinal field certain chemical substances essential 
for the bluish-green process, and leaves the gray field more 
sensitive to the complementary red stimuli which are present 
in gray light. On the other hand, it has been suggested that 
the contrast effect is of central origin and not retinal at all. 

Besides the color contrast, we also have the brightness 
contrast. A small gray square on a white background will 
appear much darker than it really is. On a black background 
it seems much lighter than it really is. 

Edge contrasts are very pronounced. If two sheets of 



VISUAL SENSATIONS 187 

colored papers, saturated red and green, or blue and yellow, 
are placed so that they partly overlap, along the edges where 
the papers meet, three will appear two narrow margins of 
intense color, one of intense red on the red paper and one of 
intense green on the green paper. This is caused by slight 
eye-movement, which allows a small strip of the retina which 
has become adapted to one color to be stimulated momen- 
tarily by the complementary color, for which it has been 
made more sensitive by its previous stimulation; hence the 
increased intensity of the sensation. 

Most marked color contrasts are seen when a narrow 
strip of gray paper is laid across several sheets of paper of 
the different spectral colors, and over all of which is placed 
a larger sheet of thin tissue paper. The gray strip then 
becomes strongly tinged in its different parts with the colors 
complementary to its several backgrounds. The part of the 
strip lying over the blue sheet appears to be yellow, while the 
part over the yellow sheet is blue; over the red sheet it ap- 
pears greenish and over the green sheet it appears reddish. 
This is usually spoken of as the Meyer Experiment. 

Contrast effects are also very marked in shadows cast in 
colored lights. If an oil-lamp is lighted in daylight the 
•shadow of any object cast on an uncolored surface, such as 
that of a white table-cloth, is strongly tinged with blue. The 
shadow, itself gray, is surrounded with the yellow lamplight 
and by contrast appears blue. 

In general, contrasts are more evident the nearer together 
the contrasting surfaces lie and the more nearly they are of 
the same degree of brightness. The more saturated the 
colors the greater the color contrast. Differences in texture 
in contrasting surfaces and division lines or boundaries of 
any kind tend to destroy contrasts. It should be noticed 
that simultaneous contrasts are set up immediately, before 
adaptation has had time to operate. This indicates that 
contrasts are at least partly independent of adaptation. 

It is evident that while the character of sensations of 



165 PSYCHOLOGY 

brightness and color is primarily determined by the nature 
of the stimulus (wave-length, amplitude, and composition of 
light-waves), nevertheless these sensations are modified by 
contrasts and by adaptation of the sensory end-organs. 

Color Zones of the Retina. — ^We may call attention here 
to the differences of color sensations aroused on different 
parts of the retina. Ordinarily, what we attend to in the 
field of vision falls upon the central part of the retina, and so, 
unless our attention is especially called to it, we are unaware 
that objects in the outlying parts of the visual field are always 
seen without color. This absence of color is explained by 
the fact that the outer zone of the retina is totally color- 
blind. By means of the "perimeter," the parts of the retina 
that are sensitive to color-stimulation may be determined. 
Light from a small red disc, when it falls upon the outer zone 
or periphery of the retina is seen as black or very dark gray. 
If the disc is then moved so that its image approaches the 
fovea or centre of the retina, it will change to a yellow, and 
finally a point will be reached nearer the fovea, where it will 
be seen in its true color. So with the other elementary 
colors, except that the points at which they appear in their 
true colors differ. 

The retina has three zones which respond differently to 
color-stimuli. Figure 60 shows a map of the color zones. 
The color zones differ somewhat in contour for different in- 
dividuals, but in the relative positions of the zones they are 
the same. 

The outermost zone responds only with sensations of 
colorless light, no matter what the nature of the stimulus is. 
The intermediate zone gives sensations of yellow and blue 
in addition to white-gray-black; while the innermost zone 
responds with all sensations of color and light. With stimuli 
of equal intensity and saturation, the red and green zones 
tend to coincide; likewise the yellow and blue. So we may 
speak of the green-red zone, the yellow-blue zone, and the 
white-black zone. These zones are not absolutely fixed, but 




■2(0' 270' 

Fig. 6o. — Perimeter chart of the color zones of the retinae. 



R.E. 




270° 270° 

Fig. 6i. — Color zones in a case of red-green blindness. 



VISUAL SENSATIONS 1 89 

vary with different intensities of color-stimuli. The map 
here given was made with stimuli of moderate intensi- 
ties. 

Color-Blindness. — A considerable number of persons are 
lacking in color- vision. It is estimated that about 2)}^ per 
cent of the male and 2 per cent of the female population are 
color-blind. The most common form of abnormal color- 
vision is partial color-blindness (dichromasia), although there 
are a few cases of total color-blindness (achromasia) . Partial 
color-blindness almost always exists as red-green blindness. 
Persons thus afflicted are unable to sense red and green. 
They see all the colors of the spectrum as yellows, blues, 
and grays. They, therefore, live in a world of two colors 
only. The reds, oranges, yellows, and parts of the greens 
appear to them in various tones of yellow, some of the greens 
and blues that lie next to each other in the spectrum appear 
as gray, while the rest of the blues and the violets appear as 
blue. In other words, they see the spectrum as a band of 
yellows in its lower part and a band of blues in its upper 
part, with a narrower band of gray between. Some of the 
reds at the lower part of the spectrum are also gray for the 
color-blind. The red-green blind, therefore, confuse red and 
green. If such a person were asked to match a red from a 
pile of many-colored yarns, he would pick out greens, grays, 
browns, and reds. Likewise, when attempting to match a 
green, he makes equally glaring errors. As an engineer or 
pilot he would make serious blunders in reading red and 
green signal-lights. This, of course, suggests the necessity 
of color tests for all who seek to enter such occupations. 
Figure 61 shows the color zones of a subject who is red- 
green blind in the right eye, with restricted color-vision in 
the left eye. (Notice that the red and green zones of the 
right eye are practically absent.) Cases of yellow-blue blind- 
ness are very rare. The cases that have been reported are 
pathological and not congenital, as are most of the cases of 
red-green blindness. 



190 PSYCHOLOGY 

Total color-blindness is, in nearly every case, congenital. 
The totally color-blind see all colors as different intensities 
of gray. They, therefore, live in a colorless world. The 
spectrum appears as a band of grays, Hghter in the centre 
and shading off into darker grays toward both ends. The 
totally color-blind eye is a dark-adapted eye; the maxi- 
mum brightness of the spectrum is, for all illuminations, in 
the region of the green, and the fovea is in some cases perma- 
nently blind, so that an object in the outer world cannot be 
fixated directly. This is the reason why totally color-blind 
persons jerk and twitch the eyes about (nystagmus) in their 
attempts to see clearly. It is probable that the total color- 
blind vision is rod-vision. Although usually inherited and 
congenital, in some cases color-blindness has been acquired 
either by the prolonged action of colored lights upon the 
retina, or through the use of drugs (nicotin, santonin), or by 
certain diseases of the retina. In its acquired form it may 
sometimes be limited to certain definite portions of the retina, 
leaving the rest of the retinal areas normal. 

Persons with normal color-vision do not all possess the 
same sensitivity for colors. Some show what has been 
called "anomalous" color- vision. They are not really color- 
blind, but their color-vision is disturbed. While they can 
see all the colors, they do not match them as the perfectly 
normal person does, indicating that the colors are not ex- 
actly the same in quality for them. 

Color Theories. — ^We have already seen that the differ- 
ence between colorless and color vision is explained by the 
theory that the former is the function of the rods, while the 
latter is attributed to the cones of the retina. But we have 
made no attempt to explain how the eye makes the further 
distinction of color-vision. What is the basis for the four 
elementary color-sensations? Are there four kinds of cones, 
one kind for red, one for yellow, one for green, and one for 
blue, each sensitive to light- waves of a certain length only? 
Such a theory is evidently too simple to explain the facts of 



VISUAL SENSATIONS I9I 

color-vision. For example, how could we then explain the 
fact that certain colors, when mixed, produce colorless, while 
others give intermediate color sensations? Yellow and blue 
give gray, while yellow and red give orange. Furthermore, 
why does adaptation to yellow increase the sensitivity to 
blue and not to red? These and other facts show that the 
relation between the four elementary color-sensations is not 
uniform. A color theory must be able to explain all the 
facts of adaptation, complementary colors, after-images, color 
mixtures, contrasts, and color-blindness. While a number of 
theories of color-vision have been proposed, no one has 
absolutely met this requirement. 

The Young-Helmholtz Theory. — This theory, first pro- 
posed by Young and later modified by Helmholtz, is based 
upon the assumption that there are only three elementary 
colors — carmine red, slightly yellowish green, and ultrama- 
rine blue. It is supposed, according to this theory, that 
there are three photochemical substances in the retina, which 
correspond to these color-sensations. The red substance 
is chiefly affected by the longer waves (red waves); the 
green substance by the medium waves (green waves), and 
the blue substance by the shorter waves (blue waves) of 
the spectrum. All the color-sensations, together with white, 
are the result of the activity of these three retinal substances. 
Each substance is supposed to be affected somewhat by any 
light-stimulus, but chiefly by its own appropriate stimulus. 
Thus, while red light has its greatest effect upon the red 
substance, it also affects the other substances slightly. Equal 
excitation of all three substances gives the sensation of white. 
Any color would then have some white light (brightness) in 
it. This would account for the fact that colors are never 
completely saturated, or pure. Black is the absence of 
stimulation. Complementary after-images are due to fatigue 
of the photochemical substance stimulated. The other sub- 
stances, then being fresh, react more powerfully to a gray 
stimulus, giving the complementary after-image. Color- 



192 PSYCHOLOGY 

blindness is due to the absence of one or more of the sub- 
stances in the retina. 

There are several serious objections to the theory: If 
white is the compound of all three colors, then in partial 
color-blindness, where one color is supposed to be absent, 
the sensation of white would be impossible. This is con- 
trary to fact, for in cases of partial color-bhndness in one 
eye only, white appears the same to both eyes. Moreover, 
in total color-blindness, sensations of white are still possible, 
although all the components of white, according to the 
theory, are absent. The fact that a mixture of green and 
blue gives a sensation (blue-green) like both components, 
while a mixture of green and red gives a sensation (yellowish 
gray) totally unlike either component color, is not satisfac- 
torily explained by the theory. In fact, the most serious 
defect in the theory seems to lie in that it does not recognize 
yellow as an elementary color, but considers it as a compound 
of red and green. In the intermediate zone of the retina and 
in red-green blindness, color-vision is yellow-blue vision. In 
these cases yellow cannot be compounded from red and 
green, since they are absent. Furthermore, yellow and blue 
are complementary colors here, as well as in normal and cen- 
tral vision. . It would therefore seem that yellow is as ele- 
mentary as blue, or red, or green, making four instead of 
three elementary colors. 

Hering Theory.— The Hering theory recognizes four ele- 
mentary color-sensations, red^ yellow, green, and blue, and two 
elementary colorless sensations, white and black. They exist 
in three pairs, the members of each pair standing in opposite 
or complementary relation to each other. The pairs are 
red and green, yellow and blue, and white and black. For 
each pair of sensations it is assumed that there is a single 
photochemical substance which has two antagonistic chemi- 
cal processes — a dissimilative and an assimilative process.' 
There are then three visual substances in the retina: a red- 
green substance, a yellow-blue substance, and a white-black 



VISUAL SENSATIONS 1 93 

substance. Red, yellow, and white light break down or 
cause dissimilation, while green, blue, and black light build 
up or cause assimilation in these three substances respectively. 
For instance, red light breaks down the red-green substance 
and green light builds it up. After the dissimilative effect 
of red light, the red-green substance tends to recover equilib- 
rium, i. e., assimilation sets in. This explains the green 
after-effect of red stimulation. Any color-stimulus not only 
acts upon its own substance, but also acts upon the white- 
black substance. This explains why all colors possess bright- 
ness. In case complementary colors (for instance, yellow 
and blue) act equally upon the yellow-blue substance at the 
same time, they neutralize each other, but, since they affect 
the white-black substance also, the result is a sensation of 
gray. If, however, these colors affect the white-black sub- 
stance in equal but opposite ways, the retinal substances 
would all be in equilibrium, and the gray which results is 
supposed to be a cortical gray (a neutral or middle gray), 
which originates in the brain centre and corresponds to the 
absence of retinal activity. This neutral gray is supposed 
to be constantly present in vision and to mix with all visual 
sensations. Only when the given complementary colors 
affect the white-black substance in different directions un- 
equally, or both affect it in the same direction, so that either 
assimiilation or dissimilation takes place, is the resulting gray 
(light gray or dark gray) , a retinal gray. The color zones of 
the retina are supposed to be determined by the presence or 
absence of the different substances. The cones of the inner- 
most zone contain all three substances, those of the inter- 
mediate zone only the yellow-blue and the white-black sub- 
stances, while those of the outermost zone contain only the 
white-black substance. Contrasts are due to the fact that 
any direct action of a stimulus on a part of the retina sets 
up a process of opposition in the parts not stimulated. 

We may object to the Hering theory on the ground that 
one-half of all the light and color sensations must be due, 



194 PSYCHOLOGY 

according to the theory, to an assimilative process in the 
substance of the sensory end-organs. This opposes our ordi- 
nary conception of the effect of stimulation. Furthermore, 
the conception of the so-called "cortical gray" makes an 
exception to the general rule that all sensory experiences 
originate in sense-organ stimulation. According to the 
theory, however, the conception of the cortical gray is neces- 
sary. For, if the white-black substance is antagonistic, as 
the other substances are, in its activities, then when both 
white and black stimulate it equally, the result must be no 
sensation at all. But, since in fact we get gray under these 
circumstances, the theory was forced to assume that it is 
a cortical and not a retinal gray. 

Ladd-Franklin Theory. — Mrs. Ladd-Franklin has proposed 
a genetic color theory, which assumes that our present color 
vision is a development from a primitive stage of colorless 
vision. Such a condition now exists in the outermost zone 
of the retina, but the central portion of the retina has devel- 
oped away from its original state, and now is able to produce 
color-sensations. The theory assumes a single photochemi- 
cal substance in both the rods and cones. But in the rods 
it exists in its original, undifferentiated form, in which any 
light-stimulus whatsoever acts upon the molecule as a whole, 
breaking it down in all its parts and giving the sensation of 
gray. In some of the cones the elements of the molecule 
have been differentiated into two parts, such that one part 
is affected only by the longer waves of the spectrum and 
gives the sensation of yellow, while the other part is affected 
by the shorter waves and gives the sensation of blue. These 
cones are found in the intermediate zone of the retina. In 
the other cones, found onl}^ in the innermost zone, the yellow 
compound has been further differentiated into two groupings, 
such that red light affects one and green light the other. 
The three stages of development may be represented as 
shown in Fig. 62. 

In the first stage the photochemical substance acts as a, 



VISUAL SENSATIONS 



195 



whole. In the second stage the two parts may act sepa- 
rately. In the third stage the three parts may act separately. 
According to the theory, complete decomposition of the 



W 



1st stage 




W 



Snd Stage 




'^ 




G 




Srd Stage j 



TV 



\ 





B 



Fig. 62. — Scheme to illustrate the Ladd-Franklin theory of color- vision. 
After Ladfl-Franklin. 

photochemical substance gives sensations of gray or white. 
Partial decomposition gives color. Thus, if both yellow and 
blue light act upon the yellow-blue cones, the result is the 
original sensation of colorless light, since both stimuli, when 
acting together, break down the molecules completely. If 
green and red act upon the green-red-blue cones, they arouse 



196 PSYCHOLOGY 

the sensation of yellow, but if green, red, and blue all act 
upon these cones, the original sensation of white or gray is 
aroused. If any color-stimulus acts alone, the molecules are 
only partially affected, and so produce sensations of color. 
One of the advantages of this theory is that it provides a 
common basis for peripheral gray, gray of very faint light, 
and the gray produced by mixing colors. 

Many other theories have been proposed, but the theories 
mentioned are the representative theories, and they serve 
to show us the nature and the dijB&culties of the problem of 
color- vision. 



CHAPTER IX 
PERCEPTION 

Perception of Objects. — We have seen that sensation is 
the consciousness of the qualities of objects. Perception, on 
the other hand, is the consciousness of objects, the result of 
the presentation of a group of physical qualities to the senses. 
For instance, we do not say that we have the sensation of 
the rose, but rather that we perceive the rose. We may 
sense its simple qualities one by one, but when color, form, 
tactual qualities, and fragrance are experienced all at the 
same time, we are aware of an object. The perception of a 
rose is not, however, the sensation of color plus the sensation 
of form, plus the sensation of fragrance, etc., it is a unitary 
experience — an experience of a single object and not of* a 
group of separate qualities. 

We may consider sensation as the awareness of the quali- 
ties of an object, while perception is the consciousness of the 
qualities of an object synthesized into an object. In sensa- 
tion, what we experience is determined by the stimulus. On 
the other hand, in perception we supplement and interpret 
the presented stimuli by past experiences. We are conscious 
of more than the group of sensations given by the stimuli. 
Past experiences are awakened and are synthesized into the 
percept. Perception is the consciousness of sense-impressions 
interpreted in terms of past experiences. In the perception 
of a book we are not only conscious of what the senses give, 
but of much more — its closed pages, printed words, chapters, 
cuts, etc., which are not presented to the sense-organs. My 
perception of apple includes the consciousness of it as a solid, 
as having a white, juicy pulp, and as having another side 
which is turned away from me. Here we have reinstatements 

197 



198 PSYCHOLOGY 

of past experiences with books and apples entering into the 
present percept. If we have had no past experience with 
books and apples, another group of revived images may sup- 
plement the sense-impression when these objects are pre- 
sented to us. We might then perceive the book as a flat 
box and the apple as an imperfect ball. A little girl from 
the tenement quarters who had never seen ferns of any kind 
called a large, flowing fern "a pot of green feathers." If an 
object which is entirely unlike anything we have known is 
presented to us, it will be experienced as a mass of sensation, 
having no significance for us — a bare sensory consciousness. 
Such a state of consciousness rarely occurs, however, for it 
is difficult to find an object wholly unique and not in some 
way related to past experience. Our simplest awareness of 
objects is supplemented by the modifications of past experi- 
ences. Sometimes, however, the amount of supplementation 
is very small. To one Hstening to the spoken words of an 
unfamiliar language, the words appear as a series of meaning- 
less sounds — naked sensations, so to speak. No supplemen- 
tation from past experience takes place, and consequently 
perception reduces to mere sensations of sound. 

More often than we think is the consciousness of objects 
supplied out of our own minds. I perceive the angles of the 
rectangular table in front of me as right angles, although the 
sensory stimuli form two acute and two obtuse angles for 
the position from which I view the table top. I perceive the 
angles as right angles, because I know from past experience 
that they are right angles. The sensations which I receive 
from the table are modified by the knowledge gained from 
past experience. How past experiences become assimilated 
into our perceptions is illustrated by the following incident: 
As I stood at the window one morning, my gaze fell upon 
the back yard of a familiar house some distance away. I was 
surprised to see that the yard, usually well kept, was filled 
with broken limestone. Wondering why the owner could so 
encumber his premises, I turned back to my work. When I 



PERCEPTION 199 

looked up some moments later, I saw that the broken, white 
limestone was only the weekly wash hanging out to dry. I 
then remembered that just before looking at the yard in the 
first instance my attention had rested for a moment upon 
the unusually white hmestone foundation of a house that 
was being built near by. The perception of the limestone 
foundation left its impress upon the mind to such a degree 
that the perception of the white linen was completely 
changed.^ 

The student will find in his own daily life abundant illus- 
trations of the fact that what we perceive depends not only 
upon the stimuH affecting the senses, but also upon what we 
have perceived in the past. ''Perception is not, as it seems, 
the mere entrance of a group of sensations, but an arousal of 
old experiences by a few newly entering sensations." ^ 

This arousal of old experiences by incoming sensations 
has been popularly termed apperception, the usual meaning 
of the term being the process by which the "raw" material 
supplied by the senses is interpreted in terms of the knowl- 
edge already in the mind. But owing to the fact that the 
term has had various different meanings and is now used 
very loosely, a better term to apply to this process is assimi- 
lation. The sensory material which enters into perception is, 
we say, assimilated by past experiences. We use the term 
assimilation to indicate the fact that perception is "actual 

' Several years ago I was very much annoyed for several weeks by the 
explosions of dynamite, which was being used to blast out the rock for a sewer 
on the avenue in front of the University. A year after the work was com- 
pleted I was startled one day by hearing an explosion of dynamite directly in 
front of the University building. I immediately v/ent to the window to see 
if the work had recommenced on the sewer line, but I was unable to locate any 
workmen on the street. It was empty. Within the next half-hour I distinctly 
heard several explosions. I was, however, unable to account for them until 
I discovered that the sounds that I had perceived as explosions came from a 
French casement window which had been opening and closing in the wind. 
The sensations of sound made by the slamming window had aroused the expe- 
riences of a year ago. So the interpretation of the sensation was determined 
by the former experiences. 

2Pillsbury: "Attention." p. 128. 



200 PSYCHOLOGY 

sensations modified and supplemented by past experiences." 
Past experiences play an important part in determining the 
character of presentations. They appear in our new experi- 
ences in various forms: vague images of previous sensations, 
motor tendencies, implicit judgments, meaning, and experi- 
ences of famiharity and recognition, any one of which may 
at times be scarcely raised above the threshold of conscious- 
ness, and may require very careful observation to detect 
its presence in perception. While past experiences are not 
always overtly present in the total process of perception, the 
nature of the percept oftentime shows that they have been 
determining elements in it. 

There are, then, two important phases in the process of 
perception: (i) The reception of sensory impressions, and (2) 
the interpretation of these impressions through past experi- 
ences already in the mind. In every-day experience it is 
usually impossible to separate these phases from each other. 
The total conscious reaction to an object is immediately com- 
bined into a single experience. Sometimes, however, the 
process of assimilation, or interpretation, is retarded. The 
sudden presentation of an unfamiliar object may be followed 
by several attempts to perceive it correctly. In each the 
attempted assimilation takes different directions, using now 
one group of past experiences and now another. The stimu- 
lus may be followed by an appreciable interval in which no 
assimilation takes place. We are unable for the moment to 
interpret the sensations; then we "come to" and recognize 
the stimulus as some definite object. If by means of the 
tachistoscope, we expose to view a complex but familiar ob- 
ject for a few thousandths of a second, the period is too short 
to permit of a completed perception. The observer may get 
a group of sensations, but he is unable to organize them into 
the experience of an object. If the exposures are repeated, 
assimilation gradually takes place and finally the object is 
correctly perceived. 

Brain pathology furnishes evidence of the existence of 



PERCEPTION 20 1 

these two phases of perception. Cases of asymholia have 
been recorded, where because of a certain brain lesion, pa- 
tients are unable to recognize familiar objects, although they 
are able to see them plainly. They receive the sensations, 
but they are not assimilated by past experiences. Other 
brain lesions may result in alexia, or inability to read. The 
words may be seen but not understood. Still another form 
of brain lesion may be followed by word deafness or loss of the 
abiHty to recognize the meaning of spoken words, although 
the ability to hear the spoken words is not interfered with. 
It would seem in these cases that the action of higher units 
of brain centres involving assimilation is cut off from the 
sense centres by the diseased condition of the cortex. 

Considered in neural terms, then, the basis of the process 
of assimilation consists in cortical modifications left behind 
by the previous neural processes, by virtue of which certain 
brain tracts are more pervious to stimuli than others. If by 
reason of past experiences a given brain tract {A) is more 
susceptible or more permeable to a given set of stimuli than 
another brain tract {B), the activity in the sense centres will 
be drained off by {A), thus giving the perception correspond- 
ing to the neural activity in {A). If we may suppose that 
there are perception levels in the cortex {i. e., that perception 
involves the activity of higher or, at least, larger areas than 
those involved in simple sensation), they may be considered 
as figured with neural patterns, corresponding to the different 
objects experienced. We may presume that each particular 
class of objects leaves a definite system of modifications or 
object patterns^ in these levels. If such a supposition de- 
scribes anything like the real neural conditions in perception, 
then we may conclude that every group of stimuli (i. e., every 
object) first arouses activity in the appropriate sense centres. 
The activity is then drained off into the particular cortical 

3 By "object patterns" we mean only that the effect of the experience of 
an object makes the neural structure more liable to act again in the same way 
when stimulations from like objects arouse it to activity. 



202 



PSYCHOLOGY 




tracts, or object patterns, which have been made permeable 
by past experiences, and which retain the modifications made 
by them. In this way past experiences are revived and in 

turn modify or supplement the 
sensations. 

The diagram (Fig. 63) will 
make the matter clear with- 
out attempting to go into the 
details of the anatomical and 
v.s. physiological facts concerned. 
It is probably not too 
much to say that all our 
higher conscious experiences 
develop out of our experiences 
of objects (perception). We 
were first introduced to a 
world of objects to which we 
had to react. Our first organ- 
ized and unified experiences 
were therefore with objects. 
In order to react to them in- 
telligently, it became neces- 
sary to know when an object 
was presented, not only what 
its presented characteristics 
were, but also to know in- 
stantly those that were not 
presented. This is possible 
only by the awakening of past experience with the object. 

It was natural, then, for the various forms of conscious- 
ness to arise around the object, and to become amalgamated 

1 It is evident that the presence of the process of assimilation makes per- 
ception a very complex conscious experience. The description of perception 
would be clearer if we had defined it as merely the reception and synthesis 
of a group of actual sensations into a unified experience corresponding to an 
object. Supplementation of the actual sensations by revived sensations could 
then be considered in the chapter on imagination, recognition of the sensations 



Fig. 63.- — V.S. — Visual stimuH (back 
yard) ; V.C. — visual centre in cor- 
tex. 

A and B, higher cortical areas; A, area in- 
volved in perception of yard filled with 
washing; B, area involved in perception 
of yard filled with limestone; Af', modi- 
fications left by past experiences with 
white clothes; M, modifications made by 
recent experiences of white limestone 
foundation. If V.C. arouses M, then B 
becomes active, and the resulting percep- 
tion will be "yard filled with limestone." 
If V.C. arouses M', then A becomes ac- 
tive and the resulting perception will be 
"yard filled with the week's washing." 
The "limestone" modification became 
dominant in the first perception because 
the experience of the stone foundation 
left certain areas temporarily more per- 
meable than others.' 



PERCEPTION 203 

or synthesized into a single efficient act of consciousness. 
We shall expect, therefore, to find in perception the begin- 
nings of imagination, judgment (recognition is a primitive 
form of judgment), and the concept (presence of meaning). 

All three forms of consciousness are present in the process 
of assimilation, which involves three important products of 
past experience: 

1. Revived sensory experiences. 

2. Recognition. 

3. Meaning. 

We have already seen that the consciousness of an object 
contains sensory elements which are revived from past ex- 
perience. In normal perception, the revived sensations are in 
keeping with the actual sensations received, and true to the 
sensible qualities of the object. If, however, we happen to 
supplement the actual sensations by a group of revived sen- 
sations which are not true to the object, the conscious result 
is an illusion. Usually in normal perception the proportional 
amount of actual sensation is large and the amount of revived 
sensation small. If, as may happen in rare cases under 
abnormal conditions, a set of revived sensations is pre- 
sented with no accompaniment of actual sensations, but pos- 
sessing the vividness of actual sensations, the conscious re- 
sult is a hallucination. 

Complication. — Complication is the term which we apply 
to the process in which an actual sensation of one of the 
qualities of an object brings up the other qualities with it. 
For instance, after my first experiences with ice, when I sense 
its coldness, its smoothness, its transparency, and its weight, 
I may, upon merely seeing a block of ice at a distance, be 
conscious of its coldness, its smoothness, and its heaviness 

awakened by an object would be treated under memory, and the fact that 
any presented object aroused meaning (signified something beyond itself) 
would be treated under the concept. But no object is ever experienced with- 
out awakening past experiences and recognitions. The synthesis of the past 
and the present is quite as fundamental in perception as the synthesis of the 
different actual sensations into a unity. 



204 PSYCHOLOGY 

without touching it. Instances of complication are very 
common. I may hear the note of a bird and the other sensa- 
tions are revived into the perception. I may hear a bell and 
perceive a street-car, smell a pleasing odor and perceive a 
rose. 

Recognition. — Recognition is a primitive form of judg- 
ment. Judgment, we shall see later, is the consciousness of 
some relationship existing between things. In its developed 
form the consciousness of relationship is explicitly experi- 
enced. In perception, recognition is implicit. When a fa- 
miliar object is brought to our notice, we experience the rela- 
tionship of the object now sensibly present to the same ob- 
ject or to similar objects as experienced in the past. When, 
for instance, we perceive a book, we instantly feel that it is 
familiar, that it is something that we have seen before. 
While we may not consciously represent to ourselves the 
related parts in the experience, yet it is nevertheless an ele- 
mentary form of judgment. We implicitly feel the relation 
of the present group of sensations to our past experience with 
books. 

Meaning. — A pure sensation has no meaning. It suggests 
nothing beyond itself. Pure sensation is the immediate 
awareness of a stimulus, before further knowledge is aroused. 
Perception, on the other hand, arouses further knowledge. 
Every object is presented to us with a background attaching 
to it. The background is the object's history, its associates, 
its functions, etc., so far as we have known them. The ob- 
ject, when presented, points out, signifies, suggests this back- 
ground to us — in short, has meaning for us. The first 
meanings which objects had for us were actions. An ob- 
ject was a thing to be reacted to in a certain way — a bottle 
meant to-put-in-mouth, ball meant to roll, knife meant to 
cut. 

The context or background which an object suggests may 
be very limited or very extended, according as our experi- 
ence with it is small or large. As we become familiar with it 



PERCEPTION 205 

it gathers meanings which are packed away in our perception 
of it. Now the thought or image of an object, carrying with 
it all the object's meanings, is a concept. The sensible pres- 
entation of the object, if it awakens a maximum of meaning, 
may function as a concept. If the emphasis in consciousness 
is placed on the meaning rather than on the sensible qualities 
of an object, the perception is conceptual in its nature. In 
so far, therefore, as perception involves meaning, it partakes 
of the quality of the concept. From the genetic point of 
view, perception is the beginning of conceptual conscious- 
ness. In the earlier stages of perception, the presence of the 
object awakened only consciousness of its sensible qualities 
and faint glimmerings of its meanings. Later, the object 
may come to be a mere symbol to which we attach a large 
number of meanings. When we say that an object is signifi- 
cant, it is plain that we are not interested in the object itself, 
but in the things that it suggests — its meanings. In a still 
later development, the name of the object may serve instead 
of the object to arouse consciousness of its meaning. When 
perception becomes so highly symbolic, the sensible qualities 
of objects form a small, if any, part of the content of con- 
sciousness. But perception does not always develop into 
concepts. We are obliged to react in a practical way to the 
objects about us and we must therefore take note of their 
sensible qualities. Much of our mental life remains on the 
perceptual plane — consciousness of objects. 

The function of perception consists in supplying a knowl- 
edge of the proximate environment of things, and thereby in- 
stigating movements of bodily adaptations. It is evident 
that if we were unaware of the presence and nature of the 
objects in our surroundings, we could not survive. Not 
only present sensory consciousness of the character of the 
object, but also past experiences of the object appear in per- 
ception and play a part in the control of movement. We 
may note in passing that perception of objects is most com- 
plete in just those features which call out our practical reac- 



2o6 PSYCHOLOGY 

tions. The objects that we handle and touch and work with 
produce in us the clearest perceptions. 

The truth or falsity of any given perception is determined 
by further experience with the object perceived. If, on ex- 
amination, the object fulfils all its functions and character- 
istics as I know them, then I consider my initial perception 
true; but if it fails to do this, I am forced to correct my per- 
ception of it. There is one other court of appeal: If other 
persons perceive the object as I do, i. e., react to it in the 
same way that I do, I have a practical proof of the truth of 
my perception. If the white powder which looks like sugar 
tastes sweet and dissolves in my tea, and all the other persons 
at the table put it in their tea, I am practically sure that my 
first perception of it as sugar is true. But if it has a saline 
taste or if others put it on meat and potatoes, I must con- 
sider my first perception false. 

Illusions. — If a group of sensory qualities of an object 
is supplemented by revived sensations that have no actual 
basis in the object, the perception is illusory. Illusions are 
due to the fact that we interpret actual sensations in terms 
of old and habitual experiences. Illusion is really an illus- 
tration of the orderly, uniform, or lawful procedure of the 
process of perception. If, for instance, I have always per- 
ceived the sensible qualities abcdefg as the object X, and 
now if adebcfg is presented, I am inclined by previous habit 
of assimilation to perceive it as the same object X. Sully 
gives the following definition of illusion : 

"Illusions depend upon the general mental law that when 
we have to do with the unfrequent, the unimportant and 
therefore unattended-to and the exceptional, we employ the 
ordinary and the familiar and the well-known as our stand- 
ard." 

Aristotle's illusion strikingly illustrates the force of habit 
in perception. Cross the index and middle fingers of the right 
hand. Rub a pencil between the tips of the fingers. Two 
pencils are perceived. Better still, roll a pea or some round 



PERCEPTION 



207 




object of about the same size between the tips of the crossed 
fingers. Two objects are distinctly perceived, in spite of the 
fact that you know that there is only one. We have formed 
the habit of interpreting two simultaneous pressure sensa- 
tions on two non-adjacent parts of the skin as coming from 
two objects. In most cases it has required two objects to 
touch the outer and the inner tips of these fingers at the 
same time. Now, when by virtue of the unusual position of 
the fingers, one object gives the same sensations, we interpret 
the sensations in the old way. 

The reverse or opposite of 
Aristotle's illusion may be pro- 
duced very clearly by touching 
the outer tips of the still crossed 
fingers with two objects. One 
object is then perceived. 

A modification of this illusion 
may be produced by blindfolding 
a subject and testing the surfaces 
of his crossed fingers for the dis- 
crimination of distances between 
the two points of a pair of com- 
passes. The shorter distances between the two points are 
uniformly judged greater than the longer distances, because 
in the normal position of the fingers the compass points must 
be farther apart in order to stimulate the same pressure 
spots. 

If the concave side of a false face is painted to represent 
the features of the human face and set up at a distance of 
twenty-five feet or more, it will appear convex. Convexity 
is a universal characteristic of faces and so we read it into the 
actual sensations coming from the concave false face. 

Illusions of movement are very common. Seated in a 
motionless railway- train, we may perceive our own train 
moving forward, whenever a train on the next track moves 
in the opposite direction. In actual perceptions of our own 



A 

Fig. 64. — Diagram showing posi- 
tion of fingers: (A) Two objects 
perceived, {B) one object per- 
ceived. 



2o8 PSYCHOLOGY 

movement forward, other objects always appear to move 
backward. The railway-car situation furnishes this condi- 
tion, the backward movement of objects. We consequently 
interpret it as our own movement forward. The same illu- 
sions may be experienced when we look down steadily at the 
water flowing under a bridge. Presently the bridge will ap- 
pear to be moving up stream, carrying us with it. The illu- 
sion of levitation may be experienced during a heavy snow- 
storm, by gazing intently at the falling snowfiakes and at 
the same time excluding everything else from the field of 
vision. The "magic swing illusion" in amusement parks is 
produced by revolving the entire room around the swing. 
To one sitting in the swing the perception of movement 
through a complete circle, over and over, is very realistic. 
All those illusions are due to our tendency to read into a 
group of actual sensations their usual accompaniments. 

There is a second general cause of illusion^ found in the 
fact that a temporary bias or tendency may be given to the 
interpretation of sensations by the "set" of consciousness at 
the moment sensory stimulation is received. The mind may 
be "full of the thought" of an object or may expect a cer- 
tain object to appear. Then if the sensory stimulation is at 
all appHcable, we are disposed to perceive that object, al- 
though it may really be another object that is presented. If 
I happen to be thinking intently about the Klondike gold- 
fields, the word "cold" heard in a fragment of conversation 
in another part of the room may be perceived as "gold." 
We are very Kable to overlook misspelled words in reading, 
because the context prepares the mind for the perception of 
the words in their correct forms. We may conclude that 
illusions are caused either by previous habits of interpreta- 
tion, or by a momentary set of the mind. 

^ James gives two main causes of illusions: "The wrong object is perceived 
either because (i) although not on this occasion the real cause, it is yet the 
habitual, inveterate, or most probable cause ... or because (2) the mind is 
temporarily full of the thought of that object. . . ." "Principles of Psy- 
chology," Vol. II, p. 86. 



PERCEPTION 209 

So far we have considered illusions as the result of the 
entrance of past experiences into the perception process. 
Illusions of this kind have been called "mixed illusions," i. e., 
revived past experiences and actual sensations are comhined 
or "mixed" in the perception of things. Such illusions are 
to be distinguished from those that are due to the effect of 
actual sensations upon each other, i. e., illusions that are due 
to the nature of peripheral stimulations. Illusions of this 
kind are called "pure illusions." For instance, a square of 
white paper surrounded by a border of green is perceived 




Fig. 65. — Miiller-Lyer illusion. 

strongly tinted with red. (Contrast effect.) The equal lines, 
a-b and b-c in the Miiller-Lyer illusion are perceived as 
unequal. 

In both of these illusions the presence of accompanying 
sensations apparently not included in the perception of the 
object is effective, nevertheless, in modifying or falsifying 
the perception. The presence of the green border and the 
oblique lines are instrumental in causing the illusions. The 
so-called "pure illusions" are constant in their appearance, 
always occurring under the given conditions. The "mixed 
illusions" are centrally aroused and variable, while the "pure 
illusions" are peripherally aroused^ and constant. 

It is claimed that illusions are not due to errors of sense, 

1 There is, however, a difference of opinion concerning the cause of the so- 
called "pure illusions." Some authorities contend that even in the perception 
of simple lines, as in the Miiller-Lyer figure, suggestions from past experience 
enter into the illusion and that, therefore, centrally aroused factors play a part 
in the errors of simple perception. (See Ladd and Woodworth: "Elements of 
Physiological Psychology," pp. 447-453.) We can, at least, say that in the 
"pure illusions" the peripheral factors are more pronounced than in the "mixed 
illusions." 



2IO PSYCHOLOGY 

but rather to our judgment, or interpretation of sensations. 
James says: "The so-called fallacy of the senses of which the 
ancient sceptics made so much account, is not a fallacy of 
the senses proper, but rather of the intellect, which interprets 
wrongly what the senses give."^ If sensation is taken to 
mean simply the conscious effect of stimuK upon us or within 
us, without reference to any existence in the outer world, 
then sensation cannot be said to be either false or true. Con- 
sciousness can be false only when it erroneously represents 
something beyond itself. An unprojected sensation of blue, 
for instance, cannot be false in itself. It is just what it is.. 
When, however, it is taken as a quaHty of an object — a blue 
paper — then it is false, if it fails to represent the true color 
of the paper. The simpler the consciousness the less chance 
for falsification. A single sense-experience (when not modi- 
fied by other experiences) reports correctly the sensible qual- 
ity it represents. 

Hallucinations. — The usual distinction between illusions 
and hallucinations consists in regarding illusions as the erro- 
neous perception of sense-impressions and hallucination as 
perception without sense-impressions. Thus, if I perceive a 
coat hung over a chair as a burglar in the room, the percep- 
tion is an illusion, but if I see my mother enter the room 
when really she is in a distant city, the perception is a hal- 
lucination. Aside from the question whether the distinction 
is absolutely valid or not, it is evident that the presence and 
absence of sense-stimuli is a physical and not a psychological 
difference. On the conscious side the two experiences are 
alike in that they appear to report what actually exists in the 
objective world. So far as the experience at the moment is 
concerned, they are not to be differentiated from perception. 
While illusions are very common occurrences in the normal 
mind, hallucinations are usually the product of a very seri- 
ously disturbed or disordered mind. Hallucinations may be 
symptoms of insanity; they appear in many cases of religious 

'"Principles of Psychology," vol. II, p. 86. 



PERCEPTION 211 

ecstasy, or in abnormally prolonged devotion to any cause; 
they are the result of the use of certain drugs or of bodily 
disease. The visions of Emanuel Swedenborg were the 
outcome of religious ecstasy, and those of Joan of Arc of 
prolonged devotion to a patriotic cause. Continued intem- 
perance in the use of alcoholic drinks may produce the hal- 
lucinations of delirium tremens, in which the victim is tor- 
mented by realistic visions. Chloroform, ether, hashish, 
and opium will also cause hallucinations. A grewsome de- 
scription of opium hallucinations may be found in Thomas 
de Quincey's " Confessions of an English Opium-Eater." Hal- 
lucination may appear in hypnotic states and during diseases 
involving high states of fever. 

Hallucinations may be experienced by persons in normal 
health, but such occurrences are extremely rare. It is said 
that Raphael had visions of the Madonna, following a pro- 
longed attempt to image her face in order to paint it. Spi- 
nello, after painting "The Fall of Lucifer," was reproached 
by the devil in person for representing him in so hideous a 
manner. 

The following is a typical case of hallucination in a nor- 
mal individual: "I sat one evening reading, when, on looking 
up from my book, I distinctly saw a school-friend of mine, 
to whom I was much attached, standing near the door. I 
was about to exclaim at the strangeness of her visit, when, 
to my horror, there were no signs of any one in the room but 
my mother. I related what I had seen to her, knowing that 
she could not have seen it, as she was sitting with her back 
to the door, nor had she heard anything unusual, and she 
was greatly amused at my scare, suggesting I had read too 
much or that I had been dreaming."^ 

Dreams oftentimes take on the appearance of reality and 
are, therefore, forms of hallucinations. The appearance of 
ghosts, apparitions, spectres, etc., may be pseudo-hallucina- 

' Quoted from the Proceedings of the Society for Psychical Research, Collec- 
tion 83, 21. 



2 1 2 PSYCHOLOGY 

tions, where there is a feeHng that they are not real exis- 
tences, but mere seeming. They are true hallucinations in 
cases where they appear to be real. 

Hallucination, like perception, may involve only one 
sense, or several senses. Those of sight and hearing are 
most common, while tactile hallucinations are relatively in- 
frequent. It is rather difficult to determine whether an ol- 
factory or gustatory experience, without apparent objective 
stimulation, is wholly subjective, or is due to slight stimuli 
which we are unable to detect. 

The neural basis for hallucinations and illusions is prob- 
ably the same as in perception. If, for any reason, the 
"neural pattern," or areas involved in normal perception, 
become centrally stimulated into full and adequate activity, 
the conscious result is the same as in perception. Blood 
pressure in the brain in fever, irritation of the neural tissue 
resulting from the toxic effect of drugs, or from fatigue fol- 
lowing continued thought on one subject, might be the occa- 
sion for setting off definite "object patterns" which are the 
neural basis for the perception of objects. In this way, we 
might understand how Raphael's continued thought of an 
imaginary Madonna's face might in the end exhaust the 
brain areas and break down the normal inertia of the brain 
cells and bring about the same form of neural activity as the 
actual presence of the object would cause. The imaginary> 
form would then be experienced as real. It would seem that 
some form of central stimulation must, in cases of hallucina- 
tion, reach either a sufficient degree of intensity, or quality, 
to set off the same brain centres and the same kind of neural 
action which is required in perception and which is initiated 
normally by sense-stimulation. 

Perception of Space 

The phrase "perception of space" is, in a way, mislead- 
ing. We do not perceive a definite unitary thing which we 
call space, whatever that may be. But, rather, we perceive 



PERCEPTION 213 

things or objects which have space relations to each other 
and to us as perceiving beings. We perceive objects in cer- 
tain positions, directions, and distances. We speak, how- 
ever, of the consciousness of these spatial relations as the 
perception of space (more properly, the perception of spaces). 
Although the consciousness of space seems very simple, it is 
nevertheless a very complex experience, and one of the most 
difficult of all our experiences to analyze. 

The first question to appear is: Is the consciousness of 
space native, or is it acquired? Do we sense space directly 
as we sense color, odor, taste, pressure, and sound, or is space 
experience the result of combining sensations into percep- 
tions? There are two opposing theories concerning it. (i) 
The nativistic theory holds that we possess a native and 
direct consciousness of space prior to all experience, just as 
we possess the consciousness of the simple qualities of ob- 
jects — color, sound, etc. (2) The empiristic, or genetic 
theory, on the other hand, holds that we have no simple or 
direct experience of space, that space experiences are wholly 
acquired, and that they are the result of the synthesis or 
combination of different sensations. According to this theory 
the development of space experiences out of the synthesis of 
sensations, which in themselves possess no space experience, 
is briefly as follows: In the main the sensations which com- 
bine to form space experience are visual, tactile, and move- 
ment sensations. They combine in various ways. To take 
a single case from pressure-sensations and movement-sensa- 
tions : We may suppose that every point' on the skin, from 
the very first, gives, when stimulated, a slightly different 
pressure-sensation from every other point. This difference 
is called "local sign." The differences are not space differ- 
ences; they are merely qualitative differences. If two points, 
A and B, four inches apart on the forearm, are similarly 
stimulated, the experience given would be that of two differ- 
ent pressure quahties, local signs A^ and B^. But now, sup- 
pose that the other hand moves from point A to point B. 



214 PSYCHOLOGY 

Then sensation of the movement from ^ to i5 would be in- 
terposed between the consciousness of local sign A^ and local 
sign B^. The two different pressure-sensations and the move- 
ment-sensation would fuse into the unitary perception of 
the space distance A-B. Eye movements may also inter- 
vene between the points A and B. A synthesis of the sensa- 
tion of a certain amount of eye movement and the two differ- 
ent pressure-sensations would then give the perception of the 
distance ^-5. The theory also assumes systems of local sign 
differences on the surface of the retina and in joint surfaces. 
From the perception of distance to the perception of surfaces 
and the perception of the third dimension is a further devel- 
opment, based chiefly upon the sensations of movement and 
local sign differences in articular sensations.^ 

James^ stands for a modification of the nativistic theory. 
He holds that there is a kind of native bigness or "volumi- 
nousness," which he calls "extensity," observable in all sen- 
sations, and that this is an attribute of all sensations, just as 
intensity is an attribute. "We call the reverberations of a 
thunderstorm more voluminous than the squeaking of a 
slate pencil; a little neuralgic pain, fine as a cobweb, in the 
face, seems less extensive than the heavy soreness of a boil, 
or the vast discomfort of a colic or a lumbago." This "volu- 
minousness," or "crude extensity," is the native experience 
from which space perception develops. Otherwise Professor 
James's point of view is thoroughly genetic. Voluminous- 
ness, or extensity, possesses no spatial order. It is not di- 
vided and subdivided into parts, as our developed space 
world is. The ordering of this primitive space is the result 
of experience, and, as in the genetic theory, local sign differ- 
ences play an important part in bringing it about. 

The author agrees with those who follow an intermediate 

1 For a more complete statement of the empirical theory of space percep- 
tion, the student is referred to Wundt's "Outlines of Psychology," third edi- 
tion, p. 113. 

^ "Principles of Psychology," vol. II, p. 134. 



PERCEPTION 215 

theory between the empirlstic and nativistic points of view. 
Some of our sensations do give an immediate '^ outspread," 
or "alongsidedness," of sensory quahties which is a crude 
spatial awareness. On the other hand, the definite space 
world, as we now know it, is the result of experience and 
development. Through various combinations of sensations 
which synthesize with the vague experience of "spreadout- 
ness," we come to have definite perceptions of position, direc- 
tion, and distance. 

The senses which furnish the original material for space 
perception are the visual and the cutaneous. Light-stimuli 
act simultaneously upon a large number of nerve-endings on 
the retina and arouse an immediate experience of "spread- 
outness." Pressure-stimuli upon the surface of the skin like- 
wise affect a large number of pressure spots simultaneously 
and set up sensations which, although alike, are sufficiently 
different to be distinguished. To these senses, therefore, 
objects seem to have a number of simultaneously existing 
parts^ which stand outside of each other. The definition and 
the order of the parts are not immediately given by sensa- 
tion, but come as the result of further experience. If, for 
instance, when the eyes are closed, a pair of compass points, 
I mm. apart, are placed upon the skin of the forearm, we 
perceive, not two distinct points, but a small expanse of 
pressure. If we separate the compass points gradually, a 
certain space interval will be reached where they will be felt 
as two points. They will not, however, be perceived as hav- 
ing a definite direction or distance from each other. One 
cannot say that one point is to the right or to the left of the 
other. There is merely the experience of the points as out- 
side or alongside of each other — a vague experience of primi- 
tive space. 

The olfactory, gustatory, and auditory senses do not, in 

^ The use of the word "part" seems to beg the question. The term does 
not, however, refer to definable spatial units, but only to the crude extension 
which we hold is natively given in the retinal and skin sensations. 



2l6 PSYCHOLOGY 

any tangible way, report objects as being "spread out" or 
having "alongsidedness," and so the sensations coming from 
them do not possess the attribute of extension. For instance, 
in auditory sensations, a number of different sounds fuse 
together and the resulting experience is not given as made 
up of parts existing alongside each other. A sound-stimulus 
does not act upon a number of discriminable different sense 
surfaces. Therefore, the sound is not experienced as having 
spatial parts or extension. It should be stated in this con- 
nection that some psychologists claim that sound-sensations 
do possess a native "voluminousness," spatial in its charac- 
ter, as the quotation from James, on a preceding page, testi- 
fies. However, this spatial character is not developed. A 
sound never comes to have, in our highest development of 
space perception, one part of it spatially set off against an- 
other part. We are never able to distinguish, say, an upper 
right-hand corner of a sound. Sensations of taste and smell, 
likewise, do not develop into distinct spatial arrangements. 

Development of Space Perception. — It is evident, when 
we inquire into the development of space perception, that 
there are two phases in the breaking up of vague space ex- 
periences into perceptions of the definite order and the ar- 
rangement of parts which the world of objects shows, (i) 
Localization — the ordering of the different parts of the skin 
surface with reference to each other, so that we are able to 
localize pressure-sensations more or less definitely on the 
various parts of the skin surfaces. (2) Projection — the pro- 
jection of sensory qualities to definite parts of a space world 
beyond the body. These two processes go on at the same 
time and are reciprocally helpful to each other. We may 
compare the size of certain objects seen with the size when 
superimposed upon the skin. Or a seen area of the skin may 
be compared with the same area as felt. 

How do we come to perceive definite positions, directions, 
and distances upon the skin surface, since they are not given 
natively? As we have indicated, it takes place through the 



PERCEPTION 217 

synthesis of different sensations. The perception of the dis- 
tance between two points on the skin is the synthesis of the 
sensation of the movement required to trace the distance 
between them with the finger or with the eyes, and the pres- 
sure-sensations themselves. By moving the hand over the 
skin surface, we trace hnes of directions and set up a series 
of differing pressure-sensations which combine with the sen- 
sations of movements made in tracing the hnes. At the 
same time the eyes may follow the movement, and the sen- 
sations arising therefrom may also enter into the perception 
of the distance on the skin. Likewise, the articular sensa- 
tions, arising from the slipping of the joint surfaces over each 
other may form a part of the perception. Localization (or 
perception of directions and distances) is most refined and 
accurate on the more mobile parts of the skin surfaces, and 
most crude and inaccurate where few tracing movements 
have been made, e. g., on the back. The perception of dis- 
tance between two points on the skin corresponds to the 
number of discernible different pressure-sensations that may 
be aroused between the points. For instance, a distance on 
the finger-tip of 4 mm. seems much greater than it does on 
the back of the hand, because the local differences in pressure 
are greater in number in a given area on the finger-tip than 
on the back of the hand. 

In the same way, distances and directions are determined 
in the outer world by movement of hand and eye over parts 
of objects exterior to the body. The greater the intensity of 
the movement required to trace the contours and distances 
between points, the greater the perceived space magnitude. 
Eye movements arouse a series of retinal sensations which 
are combined with the movement-sensations in the percep- 
tion of magnitude. If, for instance, we fixate a point A on 
the wall directly in front and then turn the eyes to the right 
through an angle of 30° to the point B, point A will trace 
corresponding lines on the right halves of the retinas, i. e., the 
image of point A will move from the central position on 



2l8 PSYCHOLOGY 

each retina to the right. The perception of the distance and 
the direction is formed out of the series of the retinal sensa- 
tions and the movement-sensations, which are interposed 
between the terminal retinal sensations. 

The original space, given by the eyes, is a vague, formless 
expanse, without definite directions or distances in it. But, 
as the sensations of movements of eye and hand, in trac- 
ing distances and directions, combine with the sensations 
aroused on the retina, the objects in the outer world take on 
form and show a definite, spatial relationship to each other. 
Cutaneous space and visual space are compared and harmo- 
nized by the fact that the same series of movement-sensations 
(movements of small extent) may measure both spaces, i. e., 
movements may trace distances felt and distances seen. 

Third Dimension. — Movement again plays an important 
part in the perception of the third dimension. The hand 
may move in all directions— up and down, right and left, to 
and from the body. For instance, if the hand moves from 
the face to an object a short distance away, the cutaneous 
sensations, caused by the contact of the hand with the face 
and with the object, have interposed between them a series 
of articular and movement sensations, which may be com- 
bined into a perception of depth. The articular and move- 
ment sensations acquire a space value in tracing surface mag- 
nitudes on the skin. Or the hand may fold upon itself, giving 
a series of articular sensations, interposed between the cuta- 
neous sensations of the hand open and the hand closed. The 
articular sensations themselves may combine with move- 
ment-sensations, just as cutaneous sensations do, into a per- 
ception of distance, so that a movement of the arm may be 
perceived as having a definite space magnitude. This is pos- 
sible because of the fact that the articular sensations possess 
an original spatial character, which becomes ordered into 
definite space perceptions through combinations with sensa- 
tions of muscular tension. 

Whether the sense of vision can give an original experi- 



PERCEPTION 219 

ence of the third dimension or not is a question which has 
been much discussed in psychology, since the time of Berke- 
ley.^ He thought that the visual estimate of the third di- 
mension is "an act of judgment, grounded on experience, 
rather than of sense," for, he said, "distance being a line 
directly endwise to the eye, it projects only one point on the 
fund of the eye, which point remains invariably the same, 
whether the distance be longer or shorter." Berkeley called 
attention to the fact that, in judging distance in the third 
dimension, we converge the eyes more for nearer objects than 
for the farther objects. The degree of convergence gives rise 
to eye-movement sensations, which act as cues to the judg- 
ment of distance. 

Berkeley was right in asserting that the perception of the 
third dimension is not a simple sense experience, but a very 
complex experience, into which sensory factors from both 
eyes enter. In the first place, visual perception involves two 
retinal images of every object perceived. If the images fall 
upon corresponding parts of the retina, the object is per- 
ceived as single; if they fall upon non-corresponding parts, it 
is seen as double. The fixation of an object brings the two 
images upon corresponding areas of the retinas, while images 
of objects nearer and farther away than the fixation-point 
fall upon non-corresponding areas. The result is that objects 
fixated are seen single, while objects which are nearer and 
farther away than the object fixated are seen double, if they 
are attended to sharply. 

Hold up a pencil in front of the eyes, with the blunt end 
nearer and about eight inches distant, and the sharpened 
end pointing directly away from the eyes. (The experiment 
will succeed more readily if the pencil is held by means of a 
pin, inserted at its middle point.) Fixate the nearer end and_ 
two pencils are seen, joining at the point fixated. Fixate the 
farther end and two pencils are seen, joining at their farther 

'Berkeley: "Essay Toward a New Theory of Vision," 1709. For discus- 
sion, see James: "Principles of Psychology," vol. II, p. 212. 



220 



PSYCHOLOGY 




ends, the right pencil extending toward the right eye and the 
left pencil toward the left eye. Fixate the middle point of 
the pencil and the two pencils are seen crossing each other 
at that point. Now, look at the pencil without attempting 
to fixate any one point. It appears as a single object. 

It is evident that when the pencil is 
seen as a single object the two disparate 
images fuse, so that the result is a single 
percept, but a percept which includes the 
experience of the object as solid (third 
dimension). Careful observation will 
show that, as the fixation-point changes, 
the disparate images fuse at the point of 
fixation. In the normal perception of 
objects the eyes are constantly moving 
over them, now fixating one point and 
now another. These different views are 
synthesized into a single percept, includ- 
ing the muscular sensations of conver- 
gence and divergence, which act as a cue 
to the distances from the eyes to the 
different parts of the object. 

The ordinary stereoscope produces a 
marked perception of the third dimension 
by causing two flat but disparate views of 
the same object to fall upon correspond- 
ing parts of the retinae. The stereoscope, 
therefore, brings about artificially the natural eye condi- 
tions, which are present in the normal perceptions of objects 
having the third dimension. The stereoscope views are 
taken with a double camera, so arranged that two views 
of an object or scene are taken — one corresponding to the 
view that the right eye gets of the object and one corre- 
sponding to the view that the left eye gets of it. When 
they are placed in the stereoscope, the right view is pre- 
sented to the right eye and the left view to the left eye. 



Fig. 66. — Diagram to 
show the different 
view of the pencil 
for each eye. The 
right eye gets an 
image of the pencil 
on its right side; the 
left eye gets an im- 
age of its left side. 
The images are dis- 
parate images. 



PERCEPTION 221 

The two views then fuse into a single picture, possessing 
the third dimension. If two pictures exactly alike, i. e., hav- 
ing no binocular disparity, are placed in the stereoscope, the 
perception of the third dimension does not take place. 

There are many acquired aids to the perception of dis- 
tances in the third dimension, effective because of past asso- 
ciations formed in our experience with things at different dis- 
tances away from us. Some of the most important are: 

Sensations of Convergence and Accommodation. — The 
eyes converge more for near objects than they do for far 
objects and the lens of the eye changes its curvature for 
objects at different distances. The varying intensities of the 
sensations arising from these eye movements become asso- 
ciated with various distances and so become suggestions of 
them. For distances greater than one hundred feet, sensa- 
tions of accommodation and convergence are of too low a 
degree of intensity to be used as cues of distances. 

Size of the Retinal Image {linear perspective) . — The farther 
away a given object is from the retina, the smaller the retinal 
image. The changes in the size of the image are not inter- 
preted as changes in the size of the object, but rather as 
changes in distance of the object from the eyes. If we know 
the size of an object, we can judge its distance by the size of 
the retinal image. 

Aerial Perspective. — Distinctness of outline of objects is 
associated with nearness and indistinctness with distance. 
Also, distant objects show a different color, due to the effect 
of the atmosphere. The distant hills and mountain ranges 
are tinged with purple. The green of woods and field becomes 
bluish, as they stretch away in the distance. In the clear 
atmosphere of the mountains the distinctness of distant ob- 
jects causes marked underestimation of these distances by 
those unused to such conditions. Quite a contrary effect is 
produced if objects are seen through a fog or a very hazy at- 
mosphere. The dimming of outline causes the objects to 
appear unusually large, "to loom up," so to speak. Since 



222 PSYCHOLOGY 

dimness is the sign of distance, the objects are perceived 
as farther away than they are. They therefore must appear 
larger. 

Light and Shadow. — Objects having projecting parts, or 
objects in reHef, show a characteristic distribution of light 
and shadow, determined by the source of light. More dis- 
tant parts are in shadow. Flat drawings may therefore be 
made to suggest the third dimension by proper shading. A 
cameo will appear as an intaglio if the source of light is be- 
low rather than above. 

Angular Perspective. — The form of a known angle sug- 
gests the distance from the eye to the surface bounded by the 
angle. The right angle of the top of the table changes its 
apparent form as it changes its distance from the eye. The 
apparent form of the angle is" a cue to its distance. 

Interposition. — Near objects cover or cut off farther ob- 
jects. We perceive the porch column to be nearer than the 
part of the house that it cuts off. We, therefore, perceive 
the house as standing behind it. 

Parallax. — If the eyes are fixed upon some object and the 
head is moved laterally, say to the right, nearer objects ap- 
pear to move to the left and objects beyond the fixation- 
point appear to move to the right. If the objects are very 
near or very far away, the apparent displacement is large. 
If the objects are nearer the fixation-point, the displacement 
is small. This parallactic displacement becomes an indica- 
tion of the relative distances of objects. 

Space Errors and Illusions. — We have already referred to 
the fact of disparity of space perception between the different 
senses, and also in the same sense. The cavity of a newly 
extracted tooth seems much larger to the tip of the tongue 
than it does to the finger-tip, or to the eyes when viewed in 
a mirror. If the points of a compass, three-fourths of an 
inch apart, are pressed against the face, the distance between 
them will feel greater, if one point is above and the other 
below the mouth, than it does when they touch the cheek. 



PERCEPTION 



223 



Filled space extent seems larger than unfilled, when both are 
applied to adjacent parts of the skin at the same time, but if 
the space extents are applied successively to the same area, 
unfilled space seems larger. 

The student may test the truth of this statement with two 
visiting cards of the same length. Notch the edge of one 
so that it will have saw-teeth three-eighths of an inch apart. 
Then cut the other card so that only two teeth appear, one 
at each extremity. Close the eyes and have someone press 
the two cards against adjacent parts of the skin. Compare 
their relative lengths. Apply the cards alternately to the 
same area and compare their apparent lengths. 

The larger number of space illusions are visual. Vertical 
distances are perceived as greater than equal horizontal dis- 
tances. Place two points vertically, one above the other, on 
a sheet of paper. Look steadily at the two points, and then 
locate a point to the right of the lower one, so that it appears 
to mark off a distance equal to the distance between the 
vertical points. Compare the distances. The horizontal dis- 
tance will appear to be larger. Compare the vertical and 
horizontal lines in Figure 67. Which are the longer? 



Fig. 67. 

The upper half of a vertical line is overestimated in com- 
parison with the low^er half. Divide a vertical line in halves 
so that the upper and lower halves appear equal. Measure 



224 



PSYCHOLOGY 



them. Select the letter "s" or the figure " 8," on a page of 
printed matter, and compare the upper and the lower halves 
of each, as to their relative sizes. Turn the page upside 
down and compare them. 

Note the following illusions and try to explain them. 



#' 



ill 



iK' 






2 




(a) ZoUner figure. 




(6) Bering Figure. 




(c) Lipps parallels. 
Fig. 68. — The lines in ZoUner's, Bering's, and Lipps's figures are parallel. The 
lower arc in the Miiller-Lyer circle is an extension of the larger arc. 



PERCEPTION 



225 




(d) Muller-Lyer circle. 



(e) Poggendor£f figure. 




(/) Jastrow illusion of area. 

Fig. 68. (Con.) — In the PoggendorfE figure the lower obhque Hne is an exten- 
sion of the upper obhque hne. The two areas in Jastrow's illusion of area 
are equal. 



One of the most interesting space illusions is the Miiller- 
Lyer illusion, the typical form of which is represented in 
Figure 69. 

Many explanations of this illusion have been offered. It 
has been suggested that the overestimation of the left-hand 
line and the underestimation of the right-hand line are 
due to the different eye movements induced when looking 
at t.h§ lines. The arrow-heads, enclosing the line on the 



2 26 PSYCHOLOGY 

right, check eye movements before they reach the extremities 
of the lines. On the other hand, the oblique lines on the 
left side of the figure lead the eye out beyond the extremities 
of the line. Since the amount of effort made in tracing a 






Fig. 69. — Miiller-Lyer illusion. 

line will affect the judgment of the length of the line, the left- 
hand line is perceived as the longer. 

The eye-movement theory may be applied to most of the 
other illusions. It is claimed that movements induced by 
perpendicular lines require more effort than movements in- 
duced by horizontal lines. Hence, perpendicular lines seem 
longer than horizontal lines of the same actual length. In 
the Miiller-Lyer circle, it is supposed, according to the eye- 
movement theory, that the eyes, in tracing the circle, tend 
to move outward from the extremities of the upper arc and 
so pass below the lower arc, making it appear too far toward 
the centre of the circle. Likewise, Jastrow's illusion of area 
might be explained as due to eye movement. The eye, in 
passing over the figures, is inclined to trace the proximate 
parts of the figures. The two lines that lie nearest together 
attract the eyes and initiate movements over them. Hence, 
a shorter movement for the upper figure and a longer move- 
ment for the lower figure is the basis for the judgment of the 
areas of the figures. 

Other theories also have been proposed for these illusions. 
The perspective theory assumes that the simple lines in these 
drawings indicate the third dimension. For instance, the 
obhque lines in the Miiller-Lyer figure suggest (subcon- 
sciously) perspective distance. The oblique lines, forming the 



PERCEPTION 227 

arrow-heads, appear nearer where they join the horizontal 
lines. The oblique lines, forming the feather-ends of the 
figure, seem farthest away where they join the horizontal 
line. Hence, the right-hand line appears nearer and the 
left-hand line farther away in perspective. The nearer right- 
hand line must then be judged shorter and the farther left- 
hand line longer, since their retinal images are of the same 
length. Vertical lines, also, according to the theory, suggest 
the third dimension and are seen in perspective. They are 
therefore foreshortened and overestimated, when compared 
with horizontal lines. 

The dynamic theory of Lipps holds that the ideas sug- 
gested by figures affect the perception of the figures. Thus a 
slender spire suggests an upward force, which suggestion en- 
ters into the perception of the spire itself; hence, the effect of 
Gothic architecture. In the Miiller-Lyer figure the right- 
hand side of the figure suggests the idea of being limited, re- 
strained, and cramped, while the left part suggests freedom, 
scope, and room for movement. These ideas affect the per- 
ception. 

The confusion theory of space illusions is based upon 
our tendency to confuse a part of a figure with the whole of 
it, or upon our habit of perceiving figures as wholes or units 
and not as parts. Thus, in the Miiller-Lyer figure, we are 
led by this tendency to judge the distances between the 
arrow-heads as a whole, rather than to judge the distance 
between the ends of the line, or points of the arrow-heads. 

There are other theories offered for the explanation of 
space errors and illusions, but they are modifications of those 
just described. It seems probable that no one theory can 
account for all the illusions. Some of the illusions may be 
due to many different influences. Perception, as we have 
seen, is a highly complex and synthetic process. Past ex- 
periences and surrounding stimuli may be variously combined 
in the perception of any given object; hence, the many the- 
ories offered to explain the falsifications of perceptions. 



228 PSYCHOLOGY 

The preceding theories of illusory space perceptions signifi- 
cantly fall into two classes: 

1. Peripheral theories, or those which attempt to explain 
space illusion as due to simultaneous sensory factors. Such 
is the eye-movement theory. 

2. Central theories, or those which undertake to explain 
illusory space perception upon the ground of past experi- 
ences. Old habits, ideas, and revived images modify and 
contort the actual sensations aroused by line and figure. 

We cannot arbitrarily decide between them. In fact, we 
are inclined to beHeve that both peripheral and central fac- 
tors enter into our perception of space. Especially so, since 
we have found that a large part of space experiences is ac- 
quired upon the basis of a very crude native endowment. 
Manifold elements, both native and acquired, have been 
worked into our space consciousness. No one theory, there- 
fore, can account for the various influences which may be 
brought to bear upon the perception of objects in space. 

Localization and Projection of Auditory Sensations. — 
Sounds are localized more or less definitely, both in the 
direction and distance from which they appear to rise. The 
localization and projection of auditory sensation does not 
signify that sounds themselves possess the attribute of spa- 
tial extension, but that they are referred to certain positions 
in the extended space world of vision, movement, and touch. 

The accuracy of the localization of direction of sounds 
varies for the different positions which the sound-stimulus 
occupies with reference to the two ears. Sounds, coming 
from any position in the extended median plane of the head, 
are poorly localized. One cannot tell whether the sound 
comes from before, above, or behind the head. Sounds 
which come from positions outside of the median plane, to 
the right or the left of the head, are located fairly accurately. 
The explanation seems to lie in the fact that the intensities 
of a sound are the same for each ear, when the stimulus is in 
the median plane. But when the stimulus is outside the 



PERCEPTION 229 

median plane, it is nearer one ear than the other, and so the 
intensity of the sound is greater for the nearer ear than it is 
for the farther ear. The relative intensities of a sound in 
the two ears would seem, then, to be a cue to the direction 
of the sound. 

This is probably a sufficient explanation for the localiza- 
tion of sounds, coming from near points. But in case the 
sound comes from a distant point, the difference in the dis- 
tances to the ears is relatively so small that the resulting 
intensities of the sound are practically equal for the two 
ears. The ability to localize a distant sound, whose intensities 
are not sufficiently different to be valuable as an indication 
of direction, has not yet found a satisfactory explanation. 
More and Fry^ suggest that the phase differences of sound- 
waves entering the ears may serve as a basis for distinguish- 
ing the direction of a sound. But this would not account 
for the fact that persons deaf in one ear are able to locate 
the direction of auditory impressions. Complex sounds, the 
human voice, musical tones containing many partial tones are 
located more easily and accurately than simple tones. It 
seems probable that the head may cast sound shadows, which 
affect the quality of a complex sound for the ear on the oppo- 
site side from its source. The higher partial tones with 
short wave-lengths would be affected more by the interven- 
ing head than the lower tones with longer wave-lengths. In 
this case the different qualities of complex sounds for the 
two ears would act as an indication of direction. Even in 
cases of persons deaf in one ear, the shape of the shell of the 
outer ear may affect the quality of a complex tone, in accor- 
dance with the direction. Persons with one ear only are un- 
able to locate accurately pure or simple tones. 

The distance from which a complex sound comes to the 
ear also affects its quality or timbre. The weaker partials 

1 Experiments made at the University of Cincinnati in 1902, but not pub- 
lished until 1907, Phil. Mag., April, 1907. Lord Rayleigh was led to the same 
conclusion by somewhat different experimental data. For a more thorough 
discussion see Myers and Wilson, British Journal of Psychology, 1908, II, 363. 



230 PSYCHOLOGY 

become less intense the greater the distance. They may drop 
out altogether at certain distances. The changing quality 
of a complex sound may, then, be the sign of its distance. 
Pure tones are located with much more difficulty than com- 
posite clangs and noises. 

Associations built up in past experience also play an im- 
portant part in judging the distances of sounds. After we 
have become acquainted with a certain sound, the intensity 
with which it reaches the ear is an index of its distance. 

Perception of Time 

There is no perception of pure time. The perception of 
time is involved in the perception of objects which appear 
to us to have temporal continuation (prolonged existence). 
Genetically, the experience of an object as a continued exis- 
tence is derived from the original and unanalyzable experi- 
ence of sense-impressions, possessing temporal extension. 
Every sense-impression begins, rises to its full intensity, and 
then wanes, thus giving a time-span, which is immediately 
apprehended. It is conceivable that even if an object existed 
only long enough to give a single, instantaneous impression 
and then disappeared completely, it would leave a time ex- 
perience because of the rise, development, and waning phases 
of the impression itself. Just as objects are perceived as 
having co-existing and extended parts (spatial spreadout- 
ness), they are also perceived as having a temporal attribute. 

There is, however, a difference of opinion among psychol- 
ogists concerning the original experience of time. We find, 
as we did in space perception, two opposing theories of time 
perception. The empiricists hold that there is no native 
and unlearned time experience — that time perception is grad- 
ually acquired out of sense experiences that are in themselves 
timeless. For instance, suppose a series of tactual sensations 
are set up on the back of the hand by tapping it with a pen- 
cil point. The tactual sensations themselves cannot, ac- 
cording to the empirical theory, give experience of time. 



PERCEPTION 231 

But there arises between any two successive taps an experi- 
ence of expectancy, a waiting for the next tap. The intensity 
of this expectancy increases until the arrival of the expected 
tap, when it wanes. So, between the successive taps, there 
is a gradually increasing and suddenly ending expectancy. 
The fusion of these tactile and expectancy experiences gives 
the perception of a time-expanse. Organic sensations (breath- 
ing, muscular strain, etc.) may also be interposed between 
other sensations and combine with them into the perception 
of time. In short, the empirical theory holds that the mind 
gets time out of the combination of different sensations, not 
that sense experiences themselves give time to the mind. 

On the other hand, the nativists hold that time is an 
original attribute of all conscious states — ^that it is a part of 
our mental content from the beginning. The author agrees 
with the nativists in affirming that an original temporal attri- 
bute attaches to all sensations, and with the empiricists in 
maintaining that developed time perceptions are the result 
of experience and come about through the synthesis of ele- 
mentary sense experiences. 

Elements of Time Perception. — The native and primary 
experiences of time are (i) simple duration and (2) succession. 
Simple duration arises out of the fact already referred to, 
that every sense-impression begins, rises to fulness, and ends. 
These phases are never separated — never given as discrete 
parts of the time interval ; but they are always bound together 
in a single moment. Each sense-impression possesses a brief 
time breadth — a simple "now" — the simplest time experi- 
ences we have. The content of this simple moment is the 
differing intensive phases through which a sense-impression 
passes from its beginning to its close. 

The normal length of time required for a sense-impression 
to mature, or develop in consciousness, varies somewhat with 
the nature of the stimulus and also with the sense stimulated. 
For ordinary impression, it is about one-half second. If a 
series of sounds are given one-half second apart, each sound 



232 PSYCHOLOGY 

duration seems adequate, but if the sounds are nearer to- 
gether, say one-fourth second apart, the duration of each sin- 
gle sound seems cramped. If the sounds are further apart 
than one-half second, the duration seems too long. In such 
cases, there is a tendency to fill in with other sense material 
— usually sensations of muscular strain, respiration, and 
organic changes. 

Experiences of succession arise out of our native ability 
to discriminate between different sensory impressions. We 
apprehend a series of sense-impressions as a succession of 
sensory "nows." 

By means of the synthetic processes of perception, the 
"nows" — the elements of time experience — are combined into 
larger and more complex units. Several sense-impressions 
with their simple durations may be combined into a single 
perception. For instance, I may perceive three or more notes 
on the piano, sounded in succession, as a single time expanse. 
A number of cutaneous sensations, following each other, may 
also be perceived as a single "now." The "now," in these 
cases, is a larger and more complex "now" than the simple 
"nows" of sensation. It is the result of the synthesis of 
sensory bits of time, or simple durations, into a present mo- 
ment which we call the psychical present. 

The Psychical Present. — The psychical present^ is that 
section of the time expanse which we feel to be presented 
now. It varies in length from about one-half Second to six 
seconds. Longer periods will not hold together, as a unit, 
but tend to break up into component parts. The content of 
the psychical present is also variable. If we listen to the 
strokes of the metronome (120 strokes a minute), it is possible 
to combine two, three, four, or six strokes into a single per- 
ception. So with other sensory impressions. A varying num- 
ber of them may be synthesized into the psychical present. 

The number of events, which we experience in any present 
moment is determined by our adaptive reactions. Whatever 

' Sometimes termed the "specious present." 



PERCEPTION 233 

corresponds to a single reaction is unified into a present mo- 
ment. If I count singly the metronome strokes, then each 
stroke occupies the present moment. If I count them by 
threes, then three strokes occupy the present moment. This 
is in harmony with the principle which we found to be true 
in the perception of objects: viz., that we perceive as com- 
bined in a single object that group of sensory impressions to 
which we make a single reaction. 

Sensory Material of Time Perceptions. — ^While all the 
senses furnish material for time perception, the most promi- 
nent content is that furnished by the auditory, kinaesthetic, 
and tactual sensations. The rhythmic movement sensations 
in organic processes (breathing and heart action) may fill in 
the interval between two auditory or tactual sensations and 
combine with them into a single moment. As one listens in- 
tently to the strokes of the metronome more than a second 
apart, the time between them is filled in and measured by 
sensations of respiration and muscular strain set up by the 
bodily attitude of listening. The duration of the interval is 
judged by the amount of change in the respiratory and strain 
sensations. Genetically, the most original time experiences 
are furnished by the muscular, tactual, and the organic sen- 
sations. These sensations are constantly present and form a 
temporal continuum against which outer events are pro- 
jected. Events which are perceived as taking place outside 
of the body are measured by the changes in the bodily proc- 
esses. Organic changes and movements and pressures are 
probably noted before the changes which take place in the 
outer world (sounds, lights, etc.). 

The Psychical Present and the Logical Present. — The 
psychical present must not be confused with the present of 
logical analysis — the logical present. While the former has 
an actually experienced duration, the logical present can be 
shown to have no duration. It is simply a point, "a knife 
edge" dividing the past from the future. Suppose we grant 
to it a very brief duration, then this duration, however short, 



234 PSYCHOLOGY 

can be analyzed logically into a part that has just passed 
and a part that is yet to come with the present separating 
them. Any duration, whatsoever, which is conceived to 
belong to the present may, therefore, be analyzed into past 
and future, leaving no present duration. If, however, we 
reahze that the logical present is theoretical and not an actu- 
ally experienced moment of time, it will present no difficul- 
ties. The psychological present is an actually experienced 
duration. 

The Past and the Future. — Only the present moment can 
be perceived. The past and the future are mental construc- 
tions which we fill out with imaginary content. We can thus 
construct a time continuum extending in two directions 
from the actually perceived present. Part of the past, our 
own, may be represented in memory, but the remote past, 
the past of the ages, which we contemplate, is the result of 
constructive imagination. The future is also ideally con- 
structed. Its content is filled in from the actually experi- 
enced events of the past and the present. Future events have 
a representation in the present moment content, in so far as 
we represent them ideally and anticipate or await their oc- 
currence. But since we can represent future events only in 
terms of past events, the future is conditioned by the past. 
It has been said that "the future is not in front of us, but 
rolls up from behind us." 

All time is regarded as belonging to one unlimited time. 
But we are unable to form any adequate conception of an 
unlimited time expanse. We cannot, for instance, conceive 
of a past that stretches back without a beginning, or a future 
that has no end. Neither can we conceive of a past with a 
beginning, or a future with an end. Such attempted con- 
ceptions, however, lead directly into the realm of metaphysics. 

The Measure of Time. — For all our practical purposes, 
we measure time objectively by the regular movement of the 
sun and stars. Clocks and watches, which divide time into 
seconds, minutes, hours, days, etc., mark off the course of 



PERCEPTION 235 

the movements and changes in the heavenly bodies. Such 
measures are purely objective. On the other hand, the psy- 
chological time, the time which we experience is subjectively 
measured by the changes in consciousness — i. e., by the num- 
ber of sensations and ideas which occupy the attention. The 
hour or day seems long or short, according as it is filled with 
few or many conscious changes. The so-called objective 
time and the psychological time do not, therefore, correspond. 
While objective time has an absolute standard of measure in 
the physical happenings (movements of sun and stars), sub- 
jective or experienced time has no such standard. Of two 
objectively equal periods, one may be experienced as much 
longer than the other. The hour which seems short to me 
may seem very long to my companion. 

When deprived of any objective measure of time, our esti- 
mation of the length of intervals is based upon changes in 
consciousness itself. The conscious material, which fills the 
time intervals, varies with the length of the interval. Very 
short intervals, less than one-half second, are filled by the 
changes through which a single sense-impression passes as it 
rises and wanes in consciousness. Intervals from one-half 
second to four seconds are filled with the muscular strain in 
eye, ear, head, neck, and other parts of the body, and inter- 
vals longer than four seconds by the muscular sensations of 
inspiration and expiration. 

Short periods of time (less than .75 seconds) seem longer 
than they are objectively, i. e., they are overestimated; long 
intervals seem shorter than they are; i. e., they are under- 
estimated. Between the shorter and longer intervals there 
is a duration which we estimate with more accuracy than any 
other. This is known as the indifference period. Its abso- 
lute length is about .75 seconds. 

Many authorities call attention to the difference in our 
estimation of the length of filled and empty time. There is, 
however, no such thing as empty time; for all time intervals 
are filled with some kind of conscious change. What is meant 



236 PSYCHOLOGY 

by empty time is a time interval which has in it no clear sen- 
sations aroused by outer stimuli, i. e., stimuli outside of the 
body. Such intervals are really filled by kinaesthetic and 
organic sensations coming from bodily changes. The differ- 
ence between the so-called empty time and filled time is the 
difference between time filled with sensations of bodily changes 
and time filled with sensations of outer changes. 

Short intervals (less than two seconds) seem longer, when 
filled with sensations of outer changes than when empty, i. e., 
when filled with kinaesthetic^ and organic sensations. In judg- 
ing intervals longer than two seconds the estimation of their 
length is reversed. Such intervals, when filled with interest- 
ing events, seem short when compared with equal intervals 
not so filled. When we are busily occupied, time flies; when 
we are not occupied, time drags. An hour filled with hap- 
penings, activities, or ideas passes before we know it, while an 
hour with few changes in it seems never-ending. 

The estimation of remembered time periods presents a 
paradox. For time that seems short in passing seems long 
when we review it in memory; and time that seems long in 
passing seems short in memory. In remembering a time 
period, we estimate its length by the number of events that 
have been crowded into it. Consequently, past intervals of 
time that were filled with events seem long, while empty in- 
tervals seem short in retrospect. 

As we grow older the time seems to pass more quickly 
than it does in youth. This is especially true of the longer 
periods of time — the year, month, and week. To the child, 
the year seems much longer than it does to the adult, but 
there probably is no appreciable difference in the shorter in- 
tervals — the minute and the second. The youth eagerly 
looks forward to the future, impatient for all that it holds 
for him. The months and years stand between him and his 
goal, and he therefore notes their course more keenly. For 

' When organic sensations become unusually intense, the time they occupy 
appears longer. 



PERCEPTION 237 

that reason the mature man, to whom most of Hfe's experi- 
ences have aheady come, and who is beginning to look back- 
ward as well as forward, regards the passing time with less 
solicitude. He is not interested, as the youth is, in the mere 
passing of time. The mental attitude of waiting, of expect- 
ing some new experience, makes us aware of the extent of 
time. When the attention is directed to the flow of time 
itself, its seeming duration is lengthened. 



CHAPTER X 
MEMORY 

The Image. — In sensation and perception, consciousness 
is awakened only when external objects are presented to 
the sense-organs. We may, therefore, refer to sensation 
and perception as presentative consciousness — consciousness 
prompted and directed by external objects. But experiences 
of objects which we have once had may be retained and re- 
vived or re-experienced again without the presence of the 
object itself, i. e., we may be conscious of objects not present 
to the senses. I may now have a mental picture of an object 
which I saw yesterday, although the object is not present. 
Such consciousness we may call re- presentative consciousness 
— consciousness internally prompted and directed. The form 
of consciousness in which the sensory content of past experi- 
ences is revived is known as imagination. In my "mind's 
eye" I can see the house I visited last week, and hear the 
voices of its inmates. These experiences are mental images. 
Mental images are conditioned upon previous perceptual ex- 
perience. The person born deaf cannot have auditory images. 
In short, without the original sensory experiences no repro- 
ductive consciousness is possible. On the other hand, any 
actual sensory experience may be re-presented by means of 
these mental images. 

The physiological basis of mental images rests (i) in the 
retention of the modifications made upon the brain by pre- 
vious experience and (2) in the recurrence of the same or 
similar nerve processes in the brain centres. The activity of 
the sense-organs, however, is not present. We may suppose 
that the neural process of perception produces some modifi- 
cation of the nervous substance in the brain, and that the 

238 



MEMORY 239 

retention of this modification is the condition for the re- 
presentation of previous experience. When we speak, as we 
often do, of mental experience being retained and reproduced 
it must be understood that a neural basis is always involved. 
It is often advantageous to speak of past experiences as stored 
in the mind and retained there until they are again revived, 
but this is only a convenient fiction of scientific psychology. 
When we treat of the association of images and ideas we shall 
continue to speak of ideas becoming associated together, and 
of the tendency of one idea to reproduce another by virtue of 
the associative links established between them. However, 
we take it for granted that the real link between ideas, and 
between past perceptions and present reproduced images, is 
the modifications retained in the brain centres. 

There has been a great deal of discussion as to whether 
the image and the perception have their basis in the same or 
in different brain centres. The question cannot be said to 
be absolutely settled, but it seems very probable that the 
image and the perception of an object involve the same brain 
centre. It is, however, necessary to assume that the nervous 
activities in the cortical centre differ slightly, because we are 
able to distinguish the difference between the perception 
and the image of an object. Since the conscious states are 
different, the brain processes which cause them must be 
different. 

It is customary to point out as the difference between 
perceptions and images the fact that the former are exter- 
nally aroused, while the latter are aroused by inner brain 
processes. While this is true, it is not a difference in the 
nature of the experiences themselves. However, the image 
does differ from perception psychologically. Careful obser- 
vation reveals the fact that images are less vivid, less distinct, 
less stable, and less coercive. Images do not stand out as 
perceptions do. They are less detailed, more fragmentary, 
and more fickle or vacillating than perceptions. Neither do 
they hold or command attention or move to action as per- 



240 PSYCHOLOGY 

captions do. All this is evident if one will compare the 
mental image of a beautiful landscape which he has seen 
with the actual perception of a similar scene. 

Now, the image is the basis of two forms of re-presentative 
mental life — memory and imagination. Memory is not only 
a re-presentation of our past experiences, but it involves 
recognition of them as our own former experiences. Imagi- 
nation, on the other hand, is either (i), the mere revival of 
sensory experience without definite reference to any particu- 
lar past event or object; or (2), the mental construction of 
events or objects which have never really taken place in our 
own experience. The latter is the popular meaning of imagi- 
nation. In many cases past perceptual experiences are re- 
vived without any recognition of them as actually having 
been a part of our experience. For instance, I may be think- 
ing of the currency bill, as pending in Congress, when a fairly 
correct and definite mental image of a silver dollar arises in 
my mind. In this case the image is evidently a revival of 
past perceptions of silver dollars, but I am not aware of it as 
such. Simple revival is known as reproductive imagination. 
Reproductive imagination is an essential stage in memory. 
Or, perhaps, it would be better to call it the basis of memory. 
However, it does not constitute a complete memory act, as 
we shall see. 

Definition of Memory. — Memory is the retention, recall, 
and recognition of past experiences. Since retention and 
recall are the stages of reproductive imagination, we may 
say that memory is reproductive imagination plus recogni- 
tion. Locke defined memory "as the power of the mind to 
revive perceptions which it has once had, with the additional 
perception annexed to them that it has had them before." 
Practically the same definition is given by James: "Memory 
proper is the knowledge of an event or fact, of which mean- 
time we have not been thinking, with the additional con- 
sciousness that we have thought or experienced it before." 
But before we can have "knowledge of an event or fact" it 



MEMORY 241 

must be retained and recalled. There are then, three steps or 
stages in a memory act: 

1. Retention. 

2. Recall. 

3. Recognition. 

(i) Retention. We have already seen that the retention 
of original impressions is based upon the modifications made 
upon brain tissue, and preserved in brain centres. Some of 
the earher psychologists thought that mental impressions 
were preserved in the "mind" as mental states, and that 
therefore they were always in existence "in the storehouse of 
memory" even when we are not conscious of them. There 
is no scientific basis for such a hypothesis. An idea as a con- 
scious fact exists only when the brain centres corresponding to 
it are active. We must therefore think of retention in terms 
of brain modifications. It is not the mind but the nervous 
system that retains our experiences. There is considerable dif- 
ference among individuals in ability to retain impressions. 
Some brains retain modifications made upon them as wax 
retains the impression of the seal, other brains lose their modi- 
fications almost as soon as they are made. Between these 
two extremes He many intermediate degrees of abihty to 
retain impressions. The normal brain has thousands of modi- 
fications wrought upon its tissue, and these modifications 
determine the nature of its activity. They represent the 
past experiences of the individual. Some of the experiences 
have cut deep into the tissue, and will never be effaced, 
others have only touched the surface, leaving very Httle trace 
behind them. 

(2) Recall. The passage of a particular sensory impulse 
through a brain centre leaves the centre capable of and liable 
to react in the same way again, even when the external stimu- 
lus is not present. When this inner neural activity takes 
place again we have the phenomenon of recall. It is reason- 
able to suppose that a given brain centre cannot arouse 
itself to activity, but that it acts only when other centres, 



242 PSYCHOLOGY 

already active, discharge impulses into the given centre. 
This supposition is backed up by the facts of mental re-pres- 
entation. Whenever a particular event, or object, is re- 
called, observation will show that we are reminded of the 
event or object by some thought or presentation already in 
consciousness. We recall past events by means of their asso- 
ciates. Any thought, percept, or image already in the mind 
tends to arouse the experiences which have been associated 
with it, because our experiences are chained together by asso- 
ciation. Given any single link in the chain, we are able, in re- 
productive consciousness, to repass to the other links by 
virtue of these associative connections. What is the real ex- 
planation of the fact that we recall our experiences in the 
general order and scheme in which they took place ? Why is 
it that the thought 6f 2 X 4 is followed by the thought of 8 ? 
Why does the sight of my friend's dog bring up the mental 
image of my friend himself? The usual answer that such 
sequences of conscious states are determined by the law of as- 
sociation, only restates, or rather generalizes, the facts as we 
know them. It does not explain them. The explanation is 
to bfe found in the nature of the nervous connection between 
the cortical areas involved in the original experiences. We 
may suppose that if the neural activity in a given brain centre 
is followed or accompanied by the stimulation of another 
centre, that the pathway between the centres is opened and 
there is a passage of nervous energy over this pathway. The 
two centres are in a condition of heightened neural activity, 
and are discharging their energy. Under such conditions it is 
reasonable to suppose that the energy of the one passes to the 
other, establishing a pathway between the centres. Then, ac- 
cording to the law of neural habit (that nervous impulses tend 
to follow the pathways that they have made on former occa- 
sions), we are able to get a general idea of what happens in 
the brain when the sight of my friend's dog is followed by 
the revived image of my friend himself. 

In psychological terms we may say that the process of 



MEMORY 243 

recall follows the law of habit — that in any series of revived 
experiences each is followed by one of its former associates, 
and any part of a system of thought tends to reinstate other 
parts of it. But since a single mental experience may have 
had a number of different associates, what determines which 
one will be recalled? Evidently, a given mental state will 
recall the associate that is most closely connected with it, or, 
to return to neural terms, recall will follow the most perme- 
able pathways. The permeability of neural pathways, or 
the closeness of association between mental states, is deter- 
mined by any one, or several, of the following factors: (i) 
Recency, (2) frequency, (3) vividness of associated experi- 
ences, (4) dominant system of thought or the conscious con- 
text at the time of recall, and (5) the plan or purpose present 
in the mind. 

Often it is the most recent associate which is revived. At 
other times it may be the most frequent associate, and at 
still other times the vividness of an associated experience 
may win the day for it. It may happen that recency and 
frequency, or recency and vividness, may work together to 
recall an experience. Illustrations of these cases may be 
easily suppHed by the student. Usually the reproductive 
tendency of our thoughts is determined by the nature of con- 
sciousness uppermost at the time — by the context. If one is 
reading or thinking about politics, the word "party" brings 
up the thought of Republican or Democrat. On the other 
hand, if the topic of thought is set upon one's social obHga- 
tions, the word "party" may bring up the thought of the 
dinner-party that he should give to repay his social debts. 
In reading or listening to a lecture it is the context that 
determines which of the many meanings of a word is to be 
recalled. Recall is also directed very largely by the purpose 
or plan which we have in mind. We recall that which serves 
the end in view. If our purpose is to remember the names 
of the Presidents of the United States, Washington is followed 
by Jefferson, rather than by Mount Vernon or the Delaware. 



244 PSYCHOLOGY 

It is plain that the context of thought and purpose usually 
work together. In practical memory the process of recall is 
selective. If a given mental state always recalled all its 
former associates impartially, memory would become a bur- 
den instead of an aid in thinking. As a matter of fact, only 
those associates which are more or less appropriate to the 
present purpose of the mind are recalled. The general direc- 
tion which recall takes is, therefore, determined by the topic 
of thought which we select. 

This form of recall, which is guided and controlled by a 
definite purpose, has been called active or voluntary recall, to 
distinguish it from the aimless reproduction in reverie and 
day-dreaming. However, we cannot directly will to recall 
a definite past experience, so that the term voluntary recall 
is misleading. The most that we can do is to search in the 
general direction in which we think the desired experience 
lies, and wait for the associative connections to revive it. In 
most cases recall takes place directly and immediately. The 
particular appropriate associative link becomes active the 
moment the attention is turned in the desired direction. For 
instance, when I wish to remember the name of the first 
President of the United States the associative connection be- 
tween "first President" and "Washington" is direct and 
immediate. But in some cases the so-called voluntary or 
active recall is indirect. Suppose I try to remember the 
name of the bookseller who sold me an old copy of Shake- 
speare. The thought of this particular copy should bring 
up directly the name of the bookseller, but it fails to do so. 
I then review, one after the other, all the other associates, 
the location of his shop, his personal appearance, the other 
books I bought of him, but no one of them is successful in 
reviving his name. I may then try the method of pronounc- 
ing the letters of the alphabet, hoping that the sound of the 
first letter of his name will possess a sufficiently strong repro- 
ductive tendency to awaken the name. This is often suc- 
cessful. Thus, under the guidance of purpose we give our 



MEMORY 245 

attention to the circumstances which we feel are in any way- 
connected with the forgotten name, and these associates do 
the work for us. 

Sometimes recall appears to be spontaneous, i. e., taking 
place without the aid of associative links. Ideas and images 
pop into consciousness without any apparent connection. 
They seem to rise up out of the depths of consciousness by 
virtue of their own force. Vivid or painful experiences will 
for days continually appear and reappear. Likewise, a tune 
will "run in the head" for hours. In some cases these ap- 
parently isolated memory fragments have been found to be 
due to subconscious associations, or to such delicate associa- 
tive connections that they escape ordinary observation. It 
is, of course, conceivable that for some time after a brgiin 
centre has been stimulated into action the recency of the 
action leaves it very susceptible to the same kind of activity, 
so that it springs into action again upon the slightest stimu- 
lus, such as changes in blood circulation and pressure, free 
energy from other active centres, etc. In such cases asso- 
ciative links are not necessary for revival. In the great ma- 
jority of cases of spontaneous recall, associative connections 
that are hidden from observation are probably responsible 
for the revival. However, some cases of recall seem to de- 
pend upon the strength and vividness of the original impres- 
sion, rather than upon associative connections. A great 
misfortune, or a great joy, will recur again and again in con- 
sciousness without any association nexus. 

(3) Recognition. The final stage of a memory process is 
recognition. When a past experience is revived and the re- 
vival is accompanied by the consciousness that it has been 
experienced before, we have memory in its exact sense. The 
chief subjective mark of recognition is the feeling of famil- 
iarity. Whenever we remember an event or object there 
comes with the sensory content of the event or object the 
added feeling-content of familiarity. The feeling of famil- 
iarity is a subjective sign of the degree of certainty of recog- 



246 PSYCHOLOGY 

nition. If the feeling of familiarity is strong we are certain 
of the recognition, but if the feeling of familiarity is weak we 
are doubtful about it. The feeling of familiarity is not, how- 
ever, absolutely trustworthy. It may accompany a false 
memory act. It often happens that a witness gives in per- 
fectly good faith erroneous descriptions of events which have 
in some way acquired a feeling of familiarity, which makes 
the event real for him. In some cases the feeling of famil- 
iarity may be detached from and aroused independently of 
the event to which it is normally attached. For instance, on 
visiting a strange place for the first time, the feeling may 
suddenly come over me that I have been in this place before 
under the same conditions — have said the same things that 
I am now saying, etc. This feeling is probably the familiarity 
feeling that belongs to some former similar experience, which 
just fails to be recalled itself. The present situation brings 
up the feeling of familiarity without the rest of the original 
experience. In other words, it is a case of incomplete 
memory. 

Recognition may be immediate or mediate. Immediate 
recognition take place without further recall. The experi- 
ence recalled is recognized on its own account. On the other 
hand, mediate recognition does not take place until the asso- 
ciates of the recalled experience are also recalled and made 
to serve as a guarantee for it. 

We often confuse recognition and memory in our every- 
day thinking. For instance, on meeting a man the second 
time we may remark that we remember him. We cannot, of 
course, remember him since he is at the moment present to 
the senses. What we really mean is that we recognize him. 
Our recognition on this occasion accompanies the perception 
of the man, not the revived image of him. Such sensory 
recognition is probably possible in a stage of development 
where memory is not yet developed. The child may be able 
to recognize objects when he sees them, long before he is 
able to reproduce images of therri when absent. Sensory 



MEMORY 247 

recognition, therefore, appears before memory is possible. 
Later, when images of former sensory experiences become 
possible, recognition attaches to them in the same manner as 
it did formerly when the actual sensory experiences were 
repeated. Thus, sensory recognition develops into ideational 
recognition. 

The function of recognition in sensory experiences rests in 
the identification of objects and experiences. It is extremely 
valuable to us as conscious beings that, after becoming ac- 
quainted with the characteristics of an object, we should be 
able to recognize that object when it appears again. By 
virtue of this recognition we can then make use of all our 
previous knowledge about the object. We know what to 
expect of it, how it will act, etc. We are, therefore, prepared 
to react to it without going through the process of learning 
its characteristics again. This we should be obHged to do 
if we did not recognize it. Thus, the child profits by the 
recognition of nurse, bottle, ball, etc., because, having learned 
their characteristics on former occasions, he can by virtue 
of recognition react more advantageously to them. Sensory 
recognition (recognition of objects) is really a primitive form 
of memory — a method of making use of past experiences. 
Memory proper appears when the reproduced mental image 
of the object is substituted for the presentation of the object 
itself. 

When the same object has been presented many times, 
recognition of it as a single former experience tends to drop 
out. We become perfectly familiar with it, and adjust our- 
selves to it automatically. The identification of it as a par- 
ticular former experience is then unnecessary. Likewise, in 
memory, when the image of an object or event has been 
repeated many times, recognition becomes less and less prom- 
inent and finally disappears, leaving the feeling of familiarity 
as its representative. For instance, when we first learned that 
Washington was the first President, or that 4X4 = 16, our 
memory of these facts included the identification of each as 



248 PSYCHOLOGY 

a definite former experience, when and where and how we 
learned it. The recognition of the memory image was neces- 
sary at first as a guarantee that it re-presented a real experi- 
ence. But later we accept the mere revival of the image 
without identification or guarantee other than itself, except 
the feeling of familiarity which survives from the earlier acts 
of recognition. Thus, much of our past experience is revived 
or re-presented without recognition or without being remem- 
bered in the strict sense of the term. All that I know and 
can reproduce of history, arithmetic, geography, etc., and my 
ability to read and write are the results of former experi- 
ences, yet I do not identify my present reproduced thoughts 
of this knowledge with these former experiences, nor am I 
aware of them as past content of my experience. I can re- 
call my name, but the chances are that I do not think of it 
as a former experience. It is merely reproduced, or re- 
presented, not explicitly recognized. However, the practical 
result is the same. It is memory with an element which has 
ceased to be useful dropped out. Reproduction under such 
conditions is really a stage of re-presentative mental life be- 
yond or above memory — a. stage of re-presentation where recog- 
nition is no longer necessary. If we were obliged to identify 
by recognition all re-presented mental content, even after we 
become familiar with it, our thinking and acting would not 
be as expeditious as it is. 

However, without recognition in the beginning re-presen- 
tative consciousness would be of little value. For it is plain 
that, unless an image has been at some time certified to as 
based upon real experience, it can function only as mere 
fancy. Recognition, then, is an important and necessary 
phase of memory. 

Organic Memory. — We often say that we remember how 
to swim, how to skate, how to play tennis, etc. It is evident 
that the modifications left behind by former practice and 
training have been retained by the organism. We can hardly 
say, however, that such cases involve conscious recall. Wher^ 



MEMORY 249 

these habits of skill are perfected the organism reacts in the 
same way in the same situation, without the aid of the con- 
scious recall of former experiences. This form of organic 
retention has been termed organic memory by certain authori- 
ties. It is mentioned here in order to differentiate it from 
memory proper. 

Individual Differences in Memory. — There is great vari- 
ation in the character of memory among different indi- 
viduals. Some have very poor memories, being unable to 
retain and recall only a small part of what they experience. 
Others have prodigious memories, retaining practically every- 
thing they see and hear. Most of us, however, possess memo- 
ries which lie between the two extremes. It does not follow 
that unusual ability of memory gives great mental power, or 
is a sign of great intelligence. Some wonderful memories 
have been found in idiots. 

Our memories are not equally good for all kinds of mate- 
rial. Some have an excellent memory for some things, and a 
very poor memory for other things. "Many a woman of 
generally feeble memory can remember every dress she has 
owned since she was ten years old," says Thorndike. The 
story is told of a certain chief of criminal records in a large 
city who knew the histories of the 25,000 criminals (contained 
on identification cards in the bureau), but who on one occa- 
sion could not remember his home telephone number. In 
many cases memory follows the types of imagination, i. e., 
some remember best what they see (visual type), others 
remember best what they hear (auditory type). Pillsbury, 
the American chess-player, possessed a wonderful visual 
imagination and memory. BHnd Tom, the blind musician, 
who could remember and reproduce long musical selections 
after hearing them once, had a very poor memory for other 
material. Such cases illustrate the fact that we possess not 
a memory, but rather, many memories. One of the most 
marked differences in the character of memory is furnished 
by the nature of recall. Some persons have what James calls 



250 PSYCHOLOGY 

desultory memory — a memory with a marked tendency to recall 
past experiences only in the order of their original occurrence. 
Such memories grind out their grists just as they were put 
into the mill, or, to use another figure, they are like phono- 
graphs, reproducing impressions in the same manner that 
they were received. An excellent illustration of this form of 
recall is found in Jane Austen's "Emma," quoted by James :^ 

. "But where could you hear it?" cried Miss Bates. "Where could 
you possibly hear it, Mr. Knightley? For it is not five minutes since 
I received Mrs. Cole's note — no, it cannot be more than five or, at 
least, ten^-for I had got my bonnet and spencer on, just ready to 
come out — I was only gone down to speak to Patty again about the 
pork — Jane was standing in the passage — were you not, Jane? For 
my mother was so afraid that we had not any salting-pan large enough. 
So I said I would see, and Jane said, 'Shall I go down instead?— for 
I think you have a little cold and Patty has been washing the kitchen.' 
'Oh, my dear,' said I — well, and just then came the note. A Miss 
Hawkins — that's all I know — a Miss Hawkins, of Bath. But, Mr. 
Knightley, how could you possibly have heard it? For the very 
moment Mr. Cole told Mrs. Cole of it, she sat down and wrote to me. 
A Miss Hawkins " 

The nature of the recall in such a sequence of reproduced 
experiences is known as "total recall," i, e., every idea acts 
as a whole in calling up the next idea. The present mental 
content is not broken up or analyzed. There is, therefore, 
no selection of, or emphasts placed upon any one part of it. 
As a result, only those experiences which have been associated 
with it as a whole are recalled — a superficial way of thinking. 
On the other hand, some persons have "logical memories" 
— memories in which recall follows the logical connection of 
thoughts or experiences. Two things which happen together 
may not have any vital relationship whatever. Therefore, in 
the logical mind, they are not put together, and so are not 
revived together in reproduction. The logical memory is 
highly selective. It breaks up the present presented situa- 
tion or thought into its more elemental parts, one of which 

1 "Principles of Psychology," vol. I, p. 571. 



MEMORY 251 

acts as a connecting-link in recall. This is known as ^'partial 
recall," i. e., a part of a thought or situation calls up the next 
thought in any sequence of mental images. Persons who re- 
call in this way possess the ability to see the subtle and logical 
connections which exist between things. They attend to the 
relationships of similarity and identity, and not merely to the 
superficial fact that two events take place at the same time 
of successively. To illustrate the difference between total 
and partial recall: Suppose the sight of the lamp on my desk 
recalls the shop where I bought it. Here the perception of 
the lamp as a whole connects with a past associate (total re- 
call). But, suppose the sight of the lamp makes me think of 
the sun. In this case the connecting-link is not the lamp as 
a whole but a part of it — its luminosity (partial recall) . 

We often speak of the memory in which recall takes place 
without logical connections as rote memory. In this case there 
are no inner relationships between the things recalled. The 
only connection rests in the fact that they have been experi- 
enced together (association by mere contiguity). Notice the 
difference in the mental connections of the terms of the list 
of nonsense-syllables: seg-bom-wek-caf-lon-dut-rin-foh-gal-gif, 
and those in the list of sense- words: teacher-school-pupil-spell- 
write-read-book-pencil-paper. When trying to remember 
them the nonsense-syllables are recalled by rote memory, while 
memory of the sense-words makes use of the logical connec- 
tions. 

In some cases we find very extensive memory of the desul- 
tory type. Great masses of material are retained, but the 
facts may not be properly organized. The result is that, as 
was the case of Dominie Sampson, "its owner can never lay 
his hands on any one article at the moment he has occasion 
for it."^ The readiness with which a memory recalls what is 
relevant to a given situation is called its "serviceableness" by 
Stout. 

'Quoted from "Guy Mannering" (in Stout's "Manual of Psychology," p. 
437-) 



252 PSYCHOLOGY 

The Training of the Memory. — Retention depends upon 
the character of the brain tissue — ^it native tenacity. "This 
is a physiological quality, given once for all with an individ- 
ual's organization, and which he can never hope to change." ^ 
According to James, this native retentiveness cannot be im- 
proved by training. While we may grant the truth of this 
statement, we must not forget that there is another impor- 
tant condition of memory, also mentioned by James, viz., the 
number and character of brain paths connecting any centre 
with other centres. In psychological terms, the greater num- 
ber of appropriate associates a fact has, the oftener it is 
thought in these connections, and the more vivid the atten- 
tion given to it, the more easily it will be recalled. This 
means that, by properly organizing and classifying the ma- 
terial of memory, by repeating it a sufficient number of times, 
and by carefully attending to the things we wish to retain, 
the memory for any particular fact or group of facts may be 
improved. 

There is an erroneous popular conception that the memory 
is something that may be taken out and exercised, as a trainer 
exercises his horse, and that the exercise of memory in any 
kind of subject-matter improves it for all kinds. We have 
touched upon this point before, when we called attention to 
the fact that we do not have a memory, but memories. Im- 
provement of the memory for language does not improve the 
memory for mathematics, except in so far as we learn meth- 
ods of study and logical organization in the study of the 
one which can be applied to the study of the other. Im- 
provement in the memory of one kind of material aids in 
the memory of another kind only in so far as the meth- 
ods of organizing and learning the different materials over- 
lap. 

We may say, then, that mere retentiveness of im- 
pressions depends upon the kind of brain tissue one has, but 
that the power of fixing and recalling any particular impres- 
^ James's "Principles of Psychology/' vol. I, p. 664. 



MEMORY 253 

sion depends upon the number of associates which we form 
with it, the frequency with which we review its connection 
and the degree of attention given to it. Further, all these 
factors except the native character of the brain are under the 
control of the individual and, therefore, one may improve 
the memory for any kind of material by practice. In fact we 
may say, in general, that any training which causes us to 
consider facts fully and thoroughly, to associate them logi- 
cally, to review them from time to time from different points 
of view, and to connect them with our interests, will improve 
the memory for such facts. 

Methods of Memorizing. — The most prominent methods 
of memorizing are: (i) Repetition, (2) Concentration, (3) Re- 
call, (4) Sectional, (5) Entire. By going over and over again 
the same material it will with a sufficient number of repetitions 
become fixed in memory, but experiments have proven this 
method to be wasteful of time. Prolonged and intense con- 
centration of the attention is much more efficacious than a 
mere mechanical repetition. Careful experiments have estab- 
lished the fact that the method of recall is the best. This 
method is more in accord with the actual conditions under 
which practical memory works. It requires the arousal of 
the memory material from within just as we recall it in actual 
memory. This method requires that after one or two im- 
pressions from without, the subject then tries to recall the ma- 
terial. If not successful, it is gone over once more, and again 
attempts are made to recall it. This process is kept up until 
the material is learned. In this way the most active partici- 
pation of the learner is called forth. In memorizing a poem, 
paragraph of prose, or other material, it is a very common 
practice to use the sectional method. The material is divided 
into small sections and each section learned separately. This, 
again, has been found wasteful. No division should be made 
in learning that is not required at the time of reproduction. 
The entire method^ is more economical and trustworthy. Each 

1 Sometimes called the "global method." 



2 54 PSYCHOLOGY 

logical unit of whatever material is to be learned should be 
gone over from beginning to end to get the best results. 

With regard to the distribution of time devoted to mem- 
orizing any given subject-matter, it has been found uneco- 
nomical to force the learning process by continuous repetitions 
without pause. It is better to give a few minutes each day 
for a number of days than to concentrate the same time of 
effort into one day. The total time required is less and the 
impressions are more firmly fixed when the time for learning 
is thus distributed than when it is all given at a single sitting 
without intermission. Fifteen minutes a day for twenty days 
brings about better results than sixty minutes a day for five 
days. 

The greater the number of appropriate logical connections 
that are attended to and emphasized in memorizing, the 
shorter the time of learning and the more permanent the 
acquisition. Thus, with one subject it required fifty-nine 
repetitions to learn a series of thirty-six nonsense-words, while 
a verse of poetry containing thirty-six words required only 
ten repetitions. Twenty-four hours later he had forgotten 
65 per cent of the nonsense-words as against 45 per cent of 
the poetry. Rational associations were, therefore, much more 
effective than the mechanical connections of rote memory, 
both in the acquisition and retention of material. 

Forgetting. — We have already seen that those things to 
which we give our attention make the deepest and most last- 
ing impressions. Attention is never evenly divided over the 
field of our experience. It is concerned with certain portions, 
while it neglects or slights others. The portions which lie 
outside the focus of attention impress us less deeply, and are 
therefore more easily lost. Consequently, forgetting is as 
normal a function of consciousness as remembering. If we 
were obliged to carry in memory all the events of our experi- 
ence we should find ourselves swamped by a great mass of 
irrelevant and insignificant details. 

But, forgetfulness normally extends to the experiences 



MEMORY 255 

which have enjoyed the fulness of attention. Although it 
may cause us great inconvenience at times, there are certain 
advantages in being freed from the burden of the past. The 
factors which lead to such lapses of memory are very numer- 
ous and refuse to be placed under any one principle. It is 
generally and popularly believed that disagreeable and painful 
experiences are not forgotten. This, however, is not true. 
There is a marked tendency to forget the disagreeable. The 
things that we do not like — our past pains and unpleasant 
experiences — drop into the background of consciousness 
sooner than the agreeable experiences. Usually we forget 
quickly that which we learn quickly, for the reason that in 
the rapidity of acquisition few associative connections , are 
formed. Examples of this are found in cramming, where 
practically everything is forgotten after examinations, or,* in 
the case of the lawyer who quickly learns all the facts bear- 
ing on a particular case but promptly forgets them after the 
trial. Things in which we lose interest are quickly forgotten, 
for the reason that we do not think of them and revive them. 
Likewise, acquisitions of memory which are not used and 
kept fresh gradually fade out of consciousness. Failure to 
use a foreign language results finally in its loss. However, a 
very instructive fact comes to light in such cases. It has 
been found that the time taken to relearn forgotten material 
is much less than that originally required, showing that the 
material was not entirely lost — that the effects of the former 
experience were really retained. This has led some authori- 
ties to declare that nothing is ever completely lost^ — that 
whatever we learn persists, and is a factor in determining 
our conscious states even though it may not be recalled. 
There is much truth in this view, although it is difficult to 
determine exactly how much the residue of our past experi- 
ences influences the character of consciousness. In some 
cases we know that the influence is considerable. It is safe 
to say that even though the form of our impressions is for- 
gotten their essential substance remains beneath the surface 



256 PSYCHOLOGY 

of memory. Every experience plays its part in the fashioning 
of our mental characteristics and leaves its mark, although 
its outline may be effaced by the lapse of time. We often 
hear persons of intelligence express the opinion that they 
have wasted their time absolutely on this or that study in 
college because they have forgotten it. The more we exam- 
ine the nature of mental life the more we are convinced of the 
error of such a view. 

Such are some of the conditions of normal forgetfulness. 
Special cases of forgetting, sometimes amounting to complete 
loss of memory, accompany certain changes and abnormal 
conditions of the organism. Old age, fatigue, bodily disease, 
accidents, exhibit peculiar forms of forgetting. With the ad- 
vancing general dissolution of the nervous material in old 
age, experiences fail more and more to be retained. This ac- 
counts for the fact that old people easily forget recent experi- 
ences, and live more and more in the memories of their youth. 
They lose their memories in the reverse order of acquisition. 
Their first experiences are the last to be forgotten. This is 
in accordance with the law of regression: The dissolution of 
the nervous system takes place in the reverse order of its develop- 
ment. The earliest functions are the most stable and the last 
to be affected. On the other hand, the latest functions are 
less stable and the first to be affected in general decay. The 
loss of memory as one gets older differs for different kinds of 
materials. The words for concrete ideas are more easily for- 
gotten than those for abstract ideas. Thus, proper nouns 
are forgotten before adjectives and verbs. The reason for 
this lies in the fact that the connections between the name of 
a particular object and the object itself are less frequently 
made than in the case of abstract ideas. The particular ob- 
ject may be thought of or imaged without the word, while 
the thought of an abstract idea involves the image of the 
word in nearly every instance. Therefore, it is more firmly 
fixed and has more associative connections for memory to 
work upon. Consequently, the weakening of associative con- 



MEMORY 257 

nections in old age affects the names for particular things be- 
fore it does those for general ideas. 

In extreme fatigue there is a marked falling off in ability 
to recall, especially the ability to recall language symbols. 
When fatigued, words come to us hesitatingly, and at times 
the right word cannot be revived at all. In cases of severe 
illness accompanied by high fever there is often a complete 
lapse of memory. A similar loss of memory may be noted 
during periods of extreme excitement or emotional distur- 
bance. An interesting lapse of memory takes place after an 
accident in which we lose consciousness. On recovery we 
find that we are unable to recall the events which led up to 
the accident. We may forget the events of minutes, hours, 
or even days preceding the accident. A blow upon the head 
may in extreme cases cause us to forget all our past experi- 
ences. Sometimes it may cause a partial loss of memory 
only — memory for a certain class of facts, a foreign language 
which we have acquired, or specific forms of sensory content 
— visual or auditory images of certain kinds. 

Defects of Memory. — Defects of memory have been classi- 
fied into three groups: (i) Amnesia, or loss of memory^ (2) 
H>^ermnesia, or exaltation of memory, and (3) Paramnesia, 
or falsification of memory.^ 

Amnesia is the inability to form or retain mental impres- 
sions. General amnesia is best represented in idiots, in cases 
of dementia, or extreme old age, when a weakened mentality 
makes the acquisition and retention of any form of memory 
material impossible. Partial amnesia is the inability to 
recall certain groups of experiences, as, for instance, when 
the patient cannot remember letters, the names of his friends, 
or the knowledge of Latin, or other languages, while memory 
for other things is normal. Such loss of memory may follow 
illness or injury to the brain. 

^ For a more extended classification, see article, "Memory (Defects of)," 
by Professor J. Jastrow, in Baldwin's "Dictionary of Philosophy and Psychol- 
ogy." 



258 PSYCHOLOGY 

Hypermnesia is an exalted power of memory. It usually 
exhibits itself as an unusual ability to remember certain 
groups of facts or impressions. This abnormality of memory 
is the basis of the marvellous feats of mental reproduction 
that are sometimes reported. Blind Tom, who could remem- 
ber a long selection of difficult music after hearing it once, 
and Seneca, who claims that he was able to repeat two thou- 
sand names in the order that they were read to him, illustrate 
this exalted form of memory. 

Paramnesia is a defect of recognition, sometimes called 
illusions of memory. In some cases a purely imaginative 
scene or event may be accompanied by a false recognition, 
making it appear to the subject as a real occurrence. Many 
of the delusions of insanity are of this nature. In more nor- 
mal individuals a pure fabrication may, after being repeated 
many times, acquire a false recognition, so that such indi- 
viduals come in time to believe their own stories. It may 
also cause that strange "feeling that all this has happened 
before" which every one has at times experienced. In such 
cases the recognition of some similar former experience mo- 
mentarily but falsely attaches itself to the present event. 
The opposite process may sometimes take place, when a 
familiar scene may temporarily appear to us as new and 
strange. Here the associative connections are severed for 
the time, and the feeling of familiarity drops away and is 
replaced by the feeling of strangeness or unfamiliarity. This 
may be produced experimentally: Pick out a familiar word 
like "and^' on a page of print. Stare at it for several min- 
utes, and presently it will appear as a foreign and unfamiliar 
thing. The explanation lies in the fact that the meaning of 
the word, its associative connections, drops away from the 
perception, taking with it the feeling of familiarity. Illusions 
of memory may also be brought about by suggestions. In 
the process of "sweating" a witness by detectives and police 
officers the normal associative connections are weakened by 
the extreme mental fatigue and excitement caused by th^ 



MEMORY 259 

inquisition. Under such conditions a highly nervous or men- 
tally unstable witness becomes a prey to suggestion, and may 
be made really to feel that he saw or took part in events 
entirely foreign to him. He may in this way be induced to 
give false testimony. Children are especially subject to falsi- 
fication of memory by suggestion. It is, therefore, extremely 
unsafe to depend upon the testimony of children, elicited by 
questions containing even the slightest suggestions in them. 
Function of Memory. — In our study of memory we should 
not lose sight of the fact that its real function is not the mere 
impartial reproduction of the past, but the revival and iden- 
tification of only those past experiences which are appropriate 
to the needs of the present situation — the selection of those 
pertinent parts of the past which can be incorporated into 
our present thinking and acting. While this selection *is 
largely controlled by the nature of past associations, the 
revival of these associations in all cases, save probably in 
mere fancy or day-dreaming, takes place within larger move- 
ments of consciousness dominated by purposes, plans, desires, 
feeling, and volitional impulses. The memory process, then, 
does not stand by itself, but is involved in larger complexes 
of consciousness in whose interests it functions. It, however, 
plays no insignificant part in our larger conscious life. It 
frees us from the narrow limits of the present moment, and 
enlarges the mental horizon by re-presenting conscious experi- 
ences of the past to which it gives the stamp of reality and 
genuineness. 



CHAPTER XI 
IMAGINATION 

Memory and Imagination. — ^We have seen that the ability 
to form mental images of past impressions is the basis of 
memory. Since imagination in its larger sense means the 
process of forming reproductive as well as productive images, 
it follows that memory and imagination overlap. Reproduc- 
tive imagination is really a part of memory. Memory in its 
exact sense is the definite recognition and identification of 
these reproductive images. But in many cases the purpose 
of thinking does not require that reproductive consciousness 
should advance to the stage of recognition. In such cases 
the sensory contents of former experiences are merely revived 
but not recognized. The reproduction of a past experience 
does not always involve the recognition of it. For example, 
in contemplating my summer outing, fleeting images of places 
and routes of travel may arise in my mind without any con- 
sciousness of the fact that I have experienced them before. 
In geometry I may image a right-angled triangle without 
recognizing it as any definite former experience. In percep- 
tion, I am constantly supplementing actual sensations given 
by the stimulus by images based upon past experiences, but 
I do not recognize or identify them as such, and so I cannot 
be said to remember them. 

The amount or degree of recognition accompanying repro- 
ductive images may vary from clear and vivid to vague and 
hazy recognition. Reproductive imagination and memory, 
therefore, shade off gradually into each other, so that it is 
sometimes difficult to say whether a given image is a memory 
image or an image of reproductive imagination. As we have 
already said, for the popular mind reproductive imagination 

260 



IMAGINATION 261 

passes for memory. This finds a partial justification in the 
overlapping of memory and reproductive imagination, and in 
the gradual shading of the one into the other. But in the 
more critical analysis of psychology we are forced to make a 
distinction between them. 

Kinds of Imagination.^ — The most striking thing about 
imagination is the formation of images of things which have 
never been given in actual experience — ''creations of the 
imagination," as the popular phrase goes. Our power to 
think events that never happened to us, to mentally picture 
things that we never saw, or even to image things that never 
existed is what is commonly meant by imagination. 

There are, then, two kinds of imagination: (i) Reproductive 
imagination — the imagination which reproduces former ex- 
periences, and (2) productive imagination, which constructs 
mentally things which we have never experienced before. 
Productive imagination may function in the interest of some 
plan or purpose, or it may act spontaneously, i. e., unre- 
strained by any purpose or voluntary effort on our part. The 
former we shall call constructive imagination, and the latter 
fancy. Constructive imagination may be further divided ac- 
cording to the general field in which it operates. The follow- 
ing is an outline of the different kinds of imagination so far 
mentioned. 

; I. Reproductive Imagination. 
II. Productive Imagination. 

1. Constructive. 

{a) Scientific. 
{h) MathematicaL 
\ (c) Literary. 
{d) Artistic. 

2. Fancy. 

I. Reproductive Imagination. — Hobbes called attention to 
two kinds of imagination, the one, "as when one imagineth a 
man or horse which he hath seen before" and the other "as 



262 PSYCHOLOGY 

when from the sight of a man at one time and a horse at 
another, we conceive in our mind a centaur." Such is the 
difference between reproductive and productive imagination. 
The former merely reproduces our past sensations and per- 
ceptions. Images are, however, never exact duplicates of 
former experiences, for otherwise we should confuse them. 
We always know the difference between the image and the 
actual sensory experience, except in the case of hallucinations. 
The psychological differences between the image and the per- 
ception we have already pointed out in the first section of 
the chapter on memory. In some abnormal conditions, these 
differences become obliterated, and the image may then take 
on the reality of perception. It is reported of an English 
portrait-painter that his reproductive visual images were so 
vivid that he required only one sitting of his subject. After 
that he was able to image the position, features, clothes, etc., 
of the subject so clearly that he could finish the portrait 
without the presence of the subject. 

II. Productive Imagination. — Reproductive imagination 
is limited in its range and variety by the range and va- 
riety of perceptual experiences. On the other hand, produc- 
tive imagination is free. This last statement needs modi- 
fication. For even productive imagination depends upon 
past experiences. Imagination cannot create a new world. 
We cannot imagine things entirely new, for the material of 
imagination must come from the past. The most fantastic 
creature of the imagination is formed out of the sensory ele- 
ments of our actual perceptions. Try as hard as we may, 
our wildest fancies cannot transcend the elementary forms of 
real experiences. Sensation is therefore the basis of all forms 
of imagination. A highly productive imagination calls for a 
broad basis of perception to draw upon. The productivity of 
imagination consists, therefore, in recombining the elements 
of old and familiar experiences into new forms. 

Reproductive images may be incorporated into productive 
imagination, as, for example, when we combine the head of 



IMAGINATION 263 

a man and the body of a horse to form a centaur. Further, 
an image of productive imagination may vary only slightly 
from some former experience, or it may differ in a marked 
degree from it. There is no absolute distinction between 
reproductive and productive imagination. The difference is a 
relative one, resting in the degree to which any given image 
corresponds to original experiences. 

The products of productive imagination may vary from 
the most fantastic dream to the great creations of art, litera- 
ture, science, invention, etc. And here we make a distinction 
between the imagination that works according to some plan 
or purpose and is controlled and guided by voluntary effort, 
and the imagination that is uncontrolled — without purpose 
or plan, capricious, and eccentric. There is a difference be- 
tween the imagination that produces a poem or drama, a 
painting or symphony, and the imagination that builds air- 
castles. The first we call (i) constructive imagination; the 
second is mere (2) fancy. These two kinds of imagination 
are sometimes called active and passive imagination. Con- 
structive imagination is active in the sense that voluntary con- 
trol is present, holding the mental construction to a definite 
plan. Fancy is passive in the sense that images arise sponta- 
neously — without any apparent active control from within. 
In this case, whatever happens to arise in consciousness is 
passively received without effort on our part to restrict or 
restrain ifi 

Constructive, or active imagination manifests itself in (a) 
scientific and (&) mathematical theories, and in {c) literary and 
{d) artistic productions, and in other ways. The builder, the 
inventor, the author, and the artist, as well as the man of 
science, all rely upon constructive imagination. Although it 
is commonly said that the artist, the builder, the author, 
etc., are free from all objective control — are free to create 
subjectively their worlds of ideal existences — this freedom is 
only relative. No creation of art can wholly disregard the 
world as it really is. The true artist must constantly keep 



264 PSYCHOLOGY 

the laws of nature in mind. Likewise, while the author may- 
invent new scenes and create ideal men and women to enact 
them, nevertheless he is controlled in the formation of his 
imaginary world by the laws of human nature. He incorpo- 
rates the real characteristics of actual scenes and real people 
in his creations. 

Sometimes the creations of genius come to the artist or 
author in a flash— "inspired," as we say. It is the common 
beHef that in such "inspired moments" genius transcends 
the ordinary world of experience and catches glimpses of a 
higher reality. However this may appeal to the popular 
mind, it will not stand the test of sober analysis. No crea- 
tion of genius can be found that does not have a broad back- 
ground of real experience behind it. The great "poem does 
not sing itself," but springs up out of a ripe and extended 
experience, even though it may suddenly appear as a happy 
thought or inspiration. It is not a transcendental importa- 
tion, but an idealized and transformed mundane experience 
awaiting just the right combination of circumstances to call 
it forth. 

On the other hand, many great productions of art and 
literature are plainly the result of prolonged and intense con- 
scious effort. They are forged by an indomitable will out of 
the raw materials of experience. With respect to the source 
from which these two phases of constructive imaginatiop 
draw their material there is no difference between them. 
They differ only in the manner in which they function, one 
easily, without effort or evident plan, and the other with 
intense effort and purpose. But both draw their material 
from the same source — experience. 

In fancy, the restraint of purpose or plan and the con- 
trolling influence of real events are in abeyance. Imagina- 
tion here has a free rein, creating for us a fantastic world of 
giants and pygmies, fairies and demons, harpies and griffins, 
or giving us an imaginary existence in day-dreaming and 
reverie, where we can build our air-castles to our heart's con- 



IMAGESTATION" 265 

tent and give expression to all manner of unrealities. Here 
are exhibited the freest images of the mind. Yet even these 
creations of imagination show their dependence upon real 
experiences. The fairy or the griffin must needs be formed 
in the moulds of past experiences. The relation of fancy to 
constructive imagination is really one of degree, depending 
upon the amount of control involved in the imaginary output. 
The line between them is not sharply marked at times, as is 
illustrated by such creations as "Alice in Wonderland" or 
"Gulliver's Travels." In both cases the products of fancy 
are subordinated to a definite constructive plan. 

The rise in consciousness of these free and uncontrolled 
images is facilitated, and their vividness increased, by the 
use of certain drugs. In hashish intoxication, the flight of 
grotesque images becomes very marked.^ Opium and alcohol 
also loosen the normal control of images and start unusual 
"flights of fancy," sometimes even causing hallucinations. 

The image of productive imagination is a new experience 
— respresenting something that has not happened to us be- 
fore. Productive images have the feeling of newness. There- 
fore the content attracts and holds the attention more vividly 
than do the contents of reproductive images. The productive 
image is filled out more completely, and is more often an end 
in itself, i. e., thought of for its own sake; while the reproduc- 
tive images, especially images of memory, are used to sym- 
bolize former experiences and are not in themselves an end 
of consciousness. As we become more and more familiar 
with objects or events, mental images which at first merely 
copy or reproduce them tend more and more to symbolize 
the objects or events, and in so doing lose much of their 
sensory content. Reproductive images, in this way, come 
to be the vehicles of meaning, i. e., stand for something be- 
sides themselves. After a number of objects or events of 
the same kind are experienced, we do not, when we wish to 
think of them, revive each and every one in terms of their 
' See James: "Principles of Psychology," vol. II, p. 121. 



266 PSYCHOLOGY 

sensory contents. We shorten the process of thinking by- 
allowing a single image to stand for all the individual images. 
In this way reproductive images begin to carry meaning and 
so to take part in a larger process — the process of conception — 
in which we think our past experiences not as single indi- 
vidual experiences, as we do in reproductive imagination, but 
in classes, or groups of experience. For instance, instead of 
calling up one by one the image of every horse that we have 
seen, we are able by means of the concept to consolidate all 
these single past experiences into one thought. A single 
image can then stand for all horses. But a single image 
cannot reproduce the sensory content of all past experiences 
with horses, nor as a symbol of them does it need to do so. 
For in the larger movements of thought attention is with- 
drawn from the image as sensory content and placed upon its 
meaning. The image, in this case, instead of reproducing a 
single past experience in all its sensory details, symbolizes all 
past experiences of the same kind. The reproductive image, 
therefore, undergoes a transformation in its function. At 
first it reproduces the sensory content of a given experience. 
Later the image may be used to symbolize all experiences 
that belong to the same class, and in so doing it drops into 
the background of consciousness, because attention shifts 
from the image to its meanings. " 

The productive image, on the other hand, just because it 
is in itself a new experience and cannot be used to symbolize 
familiar past experience, is oftentimes less vague and sketchy 
and more stable in sensory content than the reproductive 
image. 

Types of Imagination. — We have seen that the content of 
imagination is the same kind of mental stuff as that of sen- 
sation. Imagination may be carried on in terms of any one 
or all of the senses. Our images, therefore, may be visual, 
auditory, kinaesthetic, tactual, gustatory, or olfactory. In 
recalling a past or imagining a new scene, we may mentally 
picture the forms and colors, mentally hear the sounds, or 



IMAGINATION 267 

feel the actions, etc., which were present in the original ex- 
perience. Some individuals have fallen into the habit of 
using one kind of sense material more predominantly than 
any other in their mental imagery. This gives rise to types 
of imagination, according to the sensory content which is 
used in thinking. Some persons recall in terms of vision, 
others in auditory terms, and others in motor images, etc. 

Visual Type. — The visual type is most common. Past 
experiences and creations of imagination come to us in visual 
sensory material. We see the past and construct the future 
in the ''mind's eye" so to speak. Sculptors, painters, and 
architects are largely visualizers, although to be a good artist 
does not mean that one must image in terms of vision. Kin- 
sesthetic or motor images may be substituted for the visual. 
Galton found in his investigation of imagery^ a number of 
artists of note who were not of the visual type. Professor 
James says of himself: "I am myself a good draftsman and 
have a lively interest in pictures, statues, architecture, and 
decoration, and a keen sensibility to artistic efforts. But I 
am an extremely poor visualizer, and find myself often unable 
to reproduce in my mind's eye pictures which I have carefully 
examined. "2 

Auditory Type. — As a rule, musicians are of the auditory 
type of imagination. Beethoven composed his symphonies 
after losing his hearing. A good illustration of the auditory 
type is furnished by the playwriter, Legouve, who said to 
his friend Scribe: "When I write a scene, I hear and you see. 
At each phrase which I write, the voice of the person speak- 
ing strikes my ear. The diverse intonations of the actors 
sound under my pen as the words appear on my paper." 
It very often occurs that the auditory type is combined 
with the language motor type. Persons who image the 
sound of the words also image the movements of their enun- 
ciation. 

^ "Inquiries into Human Faculty," p. 84. 
2 "Principles of Psychology," vol. II, p. 53. 



268 PSYCHOLOGY 

Motor Type. — Occasionally an individual may be found 
whose imagination consists largely in images of movement. 
They habitually recall past experiences, or imagine future 
events, in terms of the movements contained in them. In 
recalling words, they image the movements of articulation. 
They think of objects in terms of the eye-movements required 
in perceiving them. The student may observe the tendency 
to image the movements of articulation by thinking such 
words as "bubble," "toddle," "pepper," and observing the 
resultant motor images. 

These three types, visual, auditory, and motor, are the 
only well-defined types. Tactual, gustatory, and olfactory 
images are possible, but they hardly ever usurp the chief 
place in the imagination of normal individuals. The case of 
Zola, the writer, is interesting because of its rarity. He 
could recall and image odors more distinctly and more easily 
than colors. Nearly every object had, when he recalled it, 
a distinctive odor. When he thought of certain streets, cities, 
or even the seasons of the year, definite images of smell 
arose in connection with the thought of them. 

The explanation of these types of imagination will prob- 
ably be found in the fact that some individuals form the 
habit of thinking in terms of some one sense to the exclusion 
of the others. A predominating interest of some kind may 
determine and fix the habit. How far heredity may be in- 
volved as a factor we do not yet know. 

A curious error has sometimes been made in applying the 
psychology of the types of imagination to education. It has 
been suggested that the "eye-minded" child should be taught 
largely through the eyes, and the "ear-minded" through the 
ears. Aside from the general principle that the young should 
receive training in just those abilities in which they are lack- 
ing (and so if a child shows inability in visual imagery, he 
should for that reason be given opportunity to develop it by 
supplying him with sensory visual material) — aside from this 
consideration, there is the further psychological fact that a 



IMAGINATION 269 

child who is lacking in visual imagery may possess an excel- 
lent visual perception, so that he is able to make accurate 
discriminations in everything that he actually sees. He may, 
therefore, be able to get more through the eye than through 
the ear in actual presentation. But what he gets through 
the eye he may translate into auditory terms, retaining, and 
recalling his acquisitions in these terms. The conditions 
which make accurate perception in the presentation of a given 
sense possible may not accompany accurate imagery in that 
sense. Imagery of the material presented may take place 
easily in terms of another sense. 

Mixed Types. — In most individualSj the contents of images 
are drawn from all the senses — sometimes from one and 
sometimes from another. One may have visual imagination 
for one kind of experience, and auditory or motor for an- 
other. Visual, auditory, and kinaesthetic sensations furnish 
most of the content of imagination. Gustatory, olfactory, 
and tactile sensations are represented less often. Probably 
no person has one type of imagination alone. 

Methods of Determining the Types of Imagination. — 
Francis Galton's statistical study of the imagination was the 
first important attempt to determine the nature of imagina- 
tion in individuals,^ He prepared a list of questions about 
mental images, which he required a large number of persons 
to answer. In each case he relied upon the direct self -obser- 
vation of his subjects. By recalling certain scenes or objects, 
we can usually determine by careful observation, the types of 
our mental images. However, more objective methods have 
been used since Galton's time. 

One simple way of determining whether a subject is visual 
or auditory in his imagery is to require him to write as rapidly 
as possible a list of objects that are characterized by well- 
marked colors. Let him continue to write for five minutes. 
Then stop him and after he has rested for some minutes 
require him to write a list of words characterized by sounds, 

1 "Inquiries into Human Faculty." 



270 PSYCHOLOGY 

allowing him the same length of time. The visual type will 
write more names of objects characterized by color, while 
the auditory type will write more names of objects character- 
ized by sounds. 

The learning method has also been used for this purpose. 
For instance, make several lists of letters, twelve in each. 
Have the subject read one of the lists, not allowing him to 
pronounce the letters to himself. See that the only impression 
he receives is the visual one. Find out how many letters 
he has learned of this list after reading it once. Then read 
another list of equal difficulty to the subject and determine 
how many of this list he can remember. Repeat each ex- 
periment ten times, taking careful note of the number and 
character of the errors. If the subject learns a much larger 
number of the lists he reads himself than of those that are 
read to him, he is visual in type. If, on the other hand, he 
learns more of the lists read to him, he is auditory in type. 
The nature of the errors is also an indication of the type of 
imagery employed. The visual type will confuse the letters 
of like appearance, c and e, p and q, u and v. The auditory 
type confuse letters of like sound, b and d and p. 

The literary productions of writers may be analyzed and 
the types of images employed determined. Thus Miss Cal- 
kins^ quotes a poem from the blind poet, Philip Marston, and 
shows that he uses only one color image in the whole poem, 
while images of sound and odor are plentiful. 

Imagery in Synaesthesia. — Cases of synassthesia furnish 
interesting instances of various kinds of imagery. Synaesthe- 
sia is the term which we give to those forms of associations 
which some individuals experience, in which the presentation 
of an object is accompanied by mental images in another 
sense. For instance, some persons image different colors 
when they hear or think of tones. The different tones have 
for them certain definite colors. The high tones have 
bright colors and the low tones the darker colors. The days 
^ "Introduction to Psychology," p. 191, 



IMAGINATION 27 1 

of the week, the months, the seasons of the year, also arouse, 
in some cases, images of color. Even the letters of the al- 
phabet, names of objects, or proper names, may be associated 
with images of color. Galton^ reports a case in which the 
vowels were imaged in colors while the consonants were al- 
ways purplish-black. This subject says: "For example, in 
the word Tuesday, when I think of each letter separately, the 
consonants are purplish-black, u is a light dove-color, e is a 
pale emerald green, and a is yellow; but when I think of the 
whole word together, the first part is light gray-green and 
the latter part is yellow." This form of synaesthesia, the 
arousal of concomitant color images, has been termed chrom- 
(Bsthesia. 

Another instance of synaesthesia is the ^^number-form " 
Some individuals always image the digits and lower numbers 
(usually not beyond one hundred) as occupying a definite 
position in space and arranged in a certain form. The hours 
of the day, the days of the week, and the months of the year 
may also have a definite imaginary arrangement which is 
always constant for the same individual, but for different 
individuals the forms are never the same. These number- 
forms will sometimes be found in several members of the 
same family. Baldwin has published number-forms of five 
different members of the same family^ and reports another 
case of three in a family who have them. He is of the opinion 
that they are hereditary in origin. Other authorities think 
that they are due to fixed associations formed between num- 
bers and spatial positions. 

Concrete and Symbolic Imagination. — So far we have 
considered images only as imitating or reproducing the sen- 
sory content of former experiences. This is concrete imagina- 
tion. If I imagine the appearance of an object, I have a 
concrete visual image; if I recall the sound of a bell, the 
image is concrete; if I imagine the feeling of velvet, the image 

^ "Inquiries into Human Faculty," p. 149. 

''Baldwin's "Dictionary of Philosophy and Psychology," pp. 654-5. 



272 PSYCHOLOGY 

is also concrete. So all imagination which brings back the 
sensory qualities of experiences is concrete. 

If, on the other hand, I recall the word or other sign 
which stands for an experience without reviving the sensory- 
experience itself, my imagination is symbolic. For instance, 
if I remember that a certain gown was red, I may merely 
recall the word and not the visual appearance. There is a 
constant tendency, as we become more and more proficient 
in the use of language, for the concrete sensory material of 
our images to be replaced by word images (verbal imagery). 
These word images are either auditory images of the words 
as heard or motor images of throat movements in articula- 
tion, or visual images of the words as printed or written. 
The blind may have tactual word images as well as auditory. 

Some persons mentally picture the form of the word 
which represents their experiences; others hear words as 
though they were spoken by themselves or by some one else; 
while others image the feeling of the word in the throat and 
lips. Victor Egger reports "that he hears his thoughts as it 
were in auditory word images." Tennyson, whose verse is 
noted for its rhythmic harmony, must have had this form of 
verbal imagery very highly developed. Still others image the 
words expressing their thoughts in terms of movements in 
throat and lips. Doctor Strieker, in his monograph on speech 
images says that he feels his thoughts in mentally half-sup- 
pressed whispers, not heard but articulated mentally. In this 
verbal-motor type of imagery, there is a strong tendency for 
the images of articulatory movements to bring about the 
movements themselves, so that those who possess this form 
of imagery are apt to whisper or talk to themselves. 

Most of us have noticed that as we grow older we lose the 
ability to recall the sensory contents of our experiences. The 
"look" and "sound" of things will not come back to us as 
vividly and accurately as they did when we were children. 
We have attributed this to a loss of imagination. It is due 
not to a loss of imagination, but to a change in the form of 



IMAGINATION 273 

imagination. The original and primary concrete image has 
been displaced by the word or the symbolic image. Our 
whole education is largely a training in translating our ex- 
periences into language symbols. We could make little prog- 
ress, if we were obliged to think our experiences in their 
original concreteness; so we use language to symbolize them. 
As we increase our facility in thinking, we find that we can- 
not stop to image all of the concrete "stuff" of experience. 
This would be a hindrance to abstract thought. We know 
that the American flag is made of stripes of red and white, 
and has a field of blue, etc., but we do not now have to pic- 
ture these forms and colors. We let the words stand for 
them without imaging the concrete realities. Galton found 
that many men of science were practically without concrete 
imagery, and concludes "that an overready perception of 
sharp mental pictures is antagonistic to the acquirement of 
habits of highly generalized and abstract thought." 

When images first began to play a part in the mental life 
of the child, they were necessarily copies of the concrete 
qualities of objects. They were vivid and detailed repro- 
ductions of sensations and perceptions. But later when he 
became familiar with the word symbols which stand for the 
qualities of the sensation, he gradually substituted the word 
symbol for the experience itself when he wished to think of 
it. In some cases verbal imagery is all that is retained of our 
past experiences. Thus I may remember that a certain man 
is tall and has red hair, but I may not be able to form any 
concrete image of him whatsoever. Indeed, as our education 
proceeds, we come more and more to rely on words rather 
than on the imagery of concrete objects in recalling the past 
or planning the future. 

The onomatopoetic tendency of certain words is an in- 
teresting fact in the substitution of language symbols for the 
concrete experiences. Such words as "hiss," "rumble," 
"crack," "swish," "buzz" attempt to imitate and preserve 
the auditory sensory qualities for which they stand. The 



274 PSYCHOLOGY 

child calls the dog "bow-wow" for the same reason. The 
imitation in the symbol of some sensory quality of the thing 
symbolized is a survival of concrete imagination. 

Image and Idea. — The term "idea " has a number of 
meanings which are in current popular use. Even in the 
literature of psychology there is no uniform usage. In the 
old traditional doctrine of the association of ideas, an idea 
is some definite permanent meaning looked upon as a psychic 
existence with powers of attraction and repulsion, analogous 
to the physical atom. Some ideas attract each other and 
flock together in the mind, while others repel each other. 
A more modern usage makes idea practically synonymous 
with concept. Idea, accordingly, is an image of an object 
plus the object's meaning. The idea of a horse is the horse- 
image together with the horse-meaning. In this case, while 
the idea includes both the image and the meaning, it em- 
phasizes the meaning rather than the sensory content of the 
image. In an idea we attend to the meaning and not to the 
image. 

A more satisfactory use of the term and one agreed upon 
by a number of psychologists is that which makes idea "the 
reproduction, with a more or less adequate image, of an 
object not actually present to the senses."^ An idea is, 
therefore, the reproduction of a perception. I have an idea 
of my dog when I recall his appearance through reproductive 
images. Ideational processes, then, are processes of mental 
reproduction in which there is a succession of ideas. 

Training of Imagination. — Since imagination, both repro- 
ductive and productive, draws its content from original sen- 
sory experiences, it follows that the beginning of imagination 
lies in accurate sensory acquaintance with things as they 
really are. The accuracy and vividness of reproductive 
images depend upon the accuracy and the vividness of the 
percept. Beyond this it may be cultivated in any particular 

'Definition of idea given in Baldwin's "Dictionary of Philosophy and 
Psychology." 



IMAGINATION 275 

line to almost any extent by continual practice. The won- 
derful visual imagery of Pillsbury, the chess-player, who was 
able, blindfolded, to play twenty games of chess, requiring 
him to image and keep in mind all the combinations of the 
chessmen in these twenty games, is due to practice in doing 
just that thing. It should be noted, however, that his ability 
to image other than chess-board situations was not above 
the average. In the first place, he made himself perfectly 
famiHar with the chess-board. Then practice in imagining 
the different positions of the men on the board made it un- 
necessary for him to have the actual board before him. While 
such overtraining of the imagination may be valuable for 
certain specialized purposes, it is doubtful as a general edu- 
cational procedure. The imagination can and should t>e 
cultivated, but not on any special kind of material to the 
exclusion of all others. 

Imagination as a Means of Supplementing the Present. — 
It is unnecessary to dwell upon the fact that imagination 
enriches the presentations of the present moment. What is 
actually given in sensory content is poor, indeed, when com- 
pared with the wealth of material poured in by the imagina- 
tion. The present is supplemented not only by the past 
through reproductive imagination, but it is modified by the 
future through creative imagination. The actual and the 
real become enlarged by the ideal. For a creature without 
imagination there is nothing but the sensory bareness of the 
actual present moment. For him there would be no revivals 
of the actual past, no constructive images of science, litera- 
ture, and art, no fairy-tales, and no myths. 

Imagination and Behavior. — In the first stages of volun- 
tarily formed motor habits, the image of movement precedes 
the movement itself. For instance, before picking up my 
pen, I may image the finger and arm movements necessary 
to perform the act. Or before pronouncing a word, I may 
form the images of the movements required in articulation. 
When habits of action are once formed, images of almost any 



276 PSYCHOLOGY 

kind may instigate an action. The image of the pen in my 
hand, or the image of the sound of the word may precede the 
proper movements of execution. So the image is a means 
of controlling our behavior. The man who successfully car- 
ries through a great activity, whether it is a military cam- 
paign or a business venture, is the man who can image his 
actions and their results — ^in other words, the man who can 
imagine the future as different from the present. The man 
of action, the captain of industry, is quite as much the man 
of imagination as the artist or the author. 

There is a general belief that it does not matter what kind 
of images one allows to take form in his thoughts so long as 
he does not commit the overt act. Psychology cannot con- 
cur in this belief. We have already seen that the kinaesthetic 
images — the images of movement — ^possess a strong tendency 
to bring about the actual movement itself. No one can 
allow the image of an act of any kind to rest in his thoughts 
without paving the way to the actual act. Sooner or later 
forms of behavior which one continues to image will become 
a reality. 

Because of this tendency of images to pass over into overt 
acts, we may say, with certain modifications, that we actually 
create our futures through the kind of images we entertain. 



CHAPTER XII 
ASSOCIATION 

Although we have already referred to the associative con- 
nections which bind experiences together, we must here con- 
sider more systematically this tendency of conscious states 
to be associated into complexes and groups which hang to- 
gether with varying degrees of cohesion. It is a matter of 
common observation that mental states are held together 
into units, groups, and constellations, so that if one member 
appears in consciousness, the other members follow.^ It is 
evident that some mental states are intimately bound to- 
gether, while others are connected more loosely. The thought 
" 2 times 2" is always followed by the thought "4"; the word 
"honesty" is less closely connected with "is the best policy," 
while the connection between the thought of a circle and the 
thought of immortaHty is still less intimate; nevertheless there 
is a connection. 

These connections are acquired in the course of experience 
and serve to hold the component parts of our mental life to- 
gether. Without these connections, there could be no such 
thing as thinking, unless a mere jumble of mental states 
could be so named. If a given mental content were just as 
liable to call up one thought as another, there would be no 
coherence of thought. Indeed, the formation of associative 
connections is the backbone of the organization of conscious- 
ness. Education is really the process of forming associative 

^ The language here is, of course, figurative. When one member of a group 
of experiences is in consciousness, we do not, like some of the old associational- 
ists, suppose that the other mental states of the group are actually in exis- 
tence outside of our consciousness, awaiting their turn to come in. We mean 
by association only the possibility of one mental state being revived when 
another is actually in consciousness. 

277 



278 PSYCHOLOGY 

connections. Our formal educational program puts together 
the things that we think should go together in the child's 
mind, and presents them to the child in organized systems of 
knowledge. We know that the mental connections thus 
formed will dominate his later thinking and acting. With 
the visual appearance of the letters "c-a-t," we associate the 
sound "cat"; with "nine times nine" we connect "81"; with 
the idea of "first President" we put the idea of " Washington," 
etc. As the child progresses along the educational route, we 
attempt to fix in his mind what we consider are the proper 
mental connections in science, literature, art, and all the 
other disciplines of knowledge. At the same time the child, 
in his daily contact with life in the home, on the street, with 
his companions, is forming his own mental connections. So 
gradually his mental content settles down into connected 
systems. What he thinks and what he does in any given 
situation depends upon the nature of the mental connections 
he has formed in the past. Even what we commonly call 
character is a matter of mental connections. The difference 
between the pessimist and the optimist, the rogue and the 
honest man, the silly dandy and the man of brains, lies in 
the nature of their mental connections. In every phase of 
mental life, from the association of simple sensations to form 
a perception, to the union of ideas and desires to form our 
ideals, associative connections are determining factors. 

Formation of Associations. — Associations are acquired 
mental connections. In attention, certain parts, phases, 
aspects, or features of a total object or situation fall succes- 
sively or simultaneously within the focus of c^pnsciousness. 
When later any part, aspect, or feature of the object or situ- 
ation is presented or is thought of, the other aspects also 
appear in consciousness. This is the fundamental fact of 
association. On hearing the noise of a street-car, which I 
cannot see, the visual image of the car arises in my conscious- 
ness because the auditory and visual sensations have been 
associated together in the actual experience of the car. 



ASSOCIATION 279 

Motor Connections. — ^There is a large group of associations 
that have not always been included in discussions of associa- 
tion for the reason that one of the terms of the association is 
not a mental state. I refer to the connections between states 
of consciousness and motor reactions. Here we have the 
whole field of motor habit formation before us. Certain acts 
become connected with certain mental states, so that the acts 
are always called out by the mental states. The sight of my 
pen on the floor prompts me to pick it up. The soldier hears 
the command ''Halt!" and stops short. The telegraph 
operator sees a word and his hand immediately executes a 
number of dots and dashes. All these are the result of ac- 
quired connections which have been formed in previous asso- 
ciations.'^ What happens in such cases is that the sensory 
brain centres discharge directly into the motor centres and 
pathways. 

Mental Connections. — The purely mental connections 
make up a large and varied group of associations. The clos- 
est associations are those between the different sensations 
which enter into a perception. Thus the color, form, odor, 
and tactual qualities of the rose form a compact and unitary 
group of experiences. If the velvety softness of the petals is 
experienced on the finger-tips, the other sensory qualities of 
the rose spring into consciousness as images, and we get an 
idea of the rose as a whole. This process of recall we have 
named complication. 

In the association of different perceptions, the terms of 
the association are not so closely combined as is the case in 
the union of sensations in the perception. The percepts 
stand apart in the combination and preserve their identity. 
They are, however, bound together by certain relations. 

1 Connections may also be acquired between one motor reaction and an- 
other. This is manifested in the so-called "chained reactions." A habit com- 
posed of several individual reactions following each other may, if started, run 
itself off, without conscious direction. The first reaction arouses the second, 
the second the third, and so on until the end. Thus if the first bar of a familiar 
piece of music is consciously executed, the rest will play itself, as it were. 



28o PSYCHOLOGY 

These relations may be established either by the fact of simul- 
taneous and successive presentations, or by the fact of simi- 
larity, contrast, cause and effect existing between presented 
objects. Objects or events that are presented at the same 
time acquire an associative connection. Likewise, if one 
object or event follows another, the two become tied together 
in a more or less effective mental union. The different parts 
and persons in the scene which I witness as I pass through a 
workshop are associated together merely because they are 
experienced together. Likewise, the different events and 
scenes of my summer's excursion are bound together because 
they follow each other. It was formerly thought that imme- 
diate succession was necessary for the formation of associa- 
tions, but it has been found that associative ties are formed 
between more or less remote members of a series of events or 
objects. Each member of the series becomes linked (in a 
lessened degree, to be sure, but nevertheless in a degree capa- 
ble of demonstration experimentally) to the member which 
comes next but one, and also to the one which comes next 
but two, etc. The associative connections decrease in 
strength as the members become more and more remote. 
This indicates that associative links form not only between 
the members serially, but that there is a tendency for suc- 
cessive presentations to form into a group in which any one 
member is linked to all the other members as well as to the 
one preceding or following it. 

It has been found experimentally that the arrangement 
of individual experiences into groups or higher units of expe- 
rience serves to intensify the associative connections and 
weld the parts more firmly together. The tendency of ex- 
periences to form into higher units is called the principle oj 
integration. For instance, the events of a summer spent in 
Europe are connected serially one to the other. But the 
events tend to form into units of experiences, which are inte- 
grated into higher or larger units than any single event. 
The German scenes and events form what we have called a 



ASSOCIATION 281 

higher unit. The French, Italian, and English experiences 
form others. What happened in Germany therefore gets a 
special German connection, and so with the other parts of 
the journey. 

We may sum up all the cases of association so far men- 
tioned under the principle of contiguity. Things that are ex- 
perienced together or thought together form associative con- 
nections. 

There is a difference between associations that are formed 
passively through mere external contiguity and those that 
are actively formed because we attend to the logical relation- 
ships which exist between the parts of our experience. The 
latter are much more permanent. Mere contiguity, however, 
rarely ever works alone in the formation of associations. 
There is almost always some thread of interest or some rela- 
tionship which ties experiences together. The most impor- 
tant of these relationships are similarity, contrast, cause and 
effect. Things that are similar or contrast sharply, or are 
related as cause and effect, attract and hold the attention 
when they are presented. They are, of course, experienced 
at the same time, also, but attention actively connects them 
because they are similar or because they contrast or stand in 
the relation of cause and effect. There are many other rela- 
tionships that bind original experiences together. Even time 
and space relations of things may be actively noted, and for 
that reason aid in forming associations. 

There are other important conditions under which the 
principles of contiguity, similarity, etc., operate in the forma- 
tion of associative connections. For instance, the presence 
of a purpose or plan in the mind will select and intensify cer- 
tain parts of our experience, and so control the formation of 
associations. Thus, the desire or purpose to remember the 
names of the voters in his district will facilitate the formation 
of name associations in the politician's mind. 

Closely related to purpose in controlling the formation of 
associations is the dominant interest in the mind at the time. 



262 PSYCHOLOGY 

Mental states are related because of interests. If one is in- 
terested in athletics, athletic scores and records form into a 
closer system of associative connections than they would if 
the interest were not present. 

Experiences that are vivid and clear are connected more 
closely than those that are unclear. This is really a repeti- 
tion of the statement already made that the things we attend 
to are associated together. The repetition of experiences 
intensifies and fixes the associative bands between them. 

Everything else being equal, the most recently formed 
associations show the strongest associative ties. As associa- 
tive groups become older, the links between the members 
rust away, so to speak. The experiences of yesterday are 
more firmly associated than those of a year ago. 

An interesting fact has been demonstrated experimentally 
concerning the age of associative connections. Of two dif- 
ferent associative connections of the same strength at any 
given time, the older is more permanent (will be retained 
longer) than the younger. If, for instance, I am now equally 
conversant with two groups of facts of the same difficulty, 
the group learned last will fade from memory first. This 
holds only when the time between the learning of the two 
groups is long enough to enable the associative connections 
of the first group to settle. For it requires a certain amount 
of time for associations to fix themselves. '^ On the other hand, 
if the learning of the one set of associations is immediately 
followed by the learning of another set, the latter sometimes 
weakens the former. This is known as retroactive inhibition. 
When, after giving my attention to one group of facts, I turn 
immediately to another group, the associations formed in the 
latter tend to inhibit those in the former. Retroactive inhi- 
bition is most active when the material of the two groups is 
of the same nature. Its effect disappears after a time. A 
familiar illustration is furnished in every-day life. It often 
happens that when we are trying to recall the name of a cer- 

1 This is known as Jost's Law. 



ASSOCIATION 283 

tain person or place which we are usually able to do, some 
one will suggest an incorrect but similar name. This sugges- 
tion blocks the proper association and we find ourselves 
unable to recall the familiar name. 

The maturing or ripening of associative connections is 
also illustrated in common experience. If, after struggling 
for some time with apparently little success to learn a certain 
system of facts, we lay aside the task until the next day, we 
are often surprised to find when we return to it that we have 
really mastered it. The associations have become fixed over 
night. 

All through this section we have spoken as though one 
mental state could form an associative connection with an- 
other mental state. Of course, the student understands that 
this is only a figurative way of stating the matter, dne 
mental state cannot form a direct connection with another 
mental state. The connections are always made through the 
brain. One of the fundamental presuppositions of this book 
is that every mental state has a physiological brain process 
back of it. We believe that when two mental states are con- 
nected or associated the real connection is made in the forma- 
tion of nervous pathways between the centres involved. The 
physiological basis for association we shall take up after dis- 
cussing the second part of association — that of associative 
recall. 

Associative Recall. — Since the time of Aristotle, there has 
been a great deal of discussion concerning the principle of 
association. He called attention to the fact that when we 
try to recall anything that is not at the moment in the mind 
we think of something that is similar, or opposite, or some- 
thing that has been associated with it in time, or space. The 
English empiricists developed these principles into the tra- 
ditional "laws of the association of ideas." They are the 
laws of similarity, contrast, and contiguity in time or space. 
An idea calls up another idea because it is similar to it, or 
because it contrasts with it, or because it has been connected 



284 PSYCHOLOGY 

with it in time or in space. Since that time these four laws 
of association have been reduced to two : the law of similarity 
and the law of contiguity. The tendency of many modern 
psychologists is to make a still further reduction. They 
assert that all cases of associative recall may be placed under 
the law of contiguity. 

The Laws of Association. — The so-called laws of associa- 
tion have been looked upon as an explanation of associative 
recall, rather than as a statement of the facts of recall. For 
instance, according to the law of similarity, one thing was 
supposed to recall another because of the similarity between 
them. Now, the statement that one idea recalls another 
because it is similar to the idea recalled, and the statement 
that a similar idea is recalled are two entirely different state- 
ments. It might well be that similar things tend to be re- 
called together, and yet the similarity may not be the cause 
of the recall. We shall return to this point later. 

It is also true that the laws of association have been con- 
cerned with the recall of associated ideas and not with the 
formation of associations. It is evident that the process of 
forming associations and the process of recalling associated 
ideas after the associative connections have been formed are 
different processes. And, further, the reason for forming 
the associations may not be the reason why the associated 
ideas are recalled. To this point we shall also return. 

Contiguity. — Accepting the prevailing theory that in the 
law of association we may .find the explanation of associative 
recall, we incHne to the belief that a single law — the law of con- 
tiguity — will cover all cases of associative recall. This law 
may be stated as follows: Objects or events which have been 
experienced together, will be revived together whenever any 
member of the group is present in consciousness. Any mem- 
ber of an associated group of experiences tends to awaken 
the other members of the group. Here again psychological 
language is figurative to a high degree. We often say, for 
instance, that one idea has an attraction for, a tendency to 



ASSOCIATION 285 

suggest, the ideas which have been associated with it. What 
is really meant is that the neural process involved in the 
given idea tends to spread to other centres which have been 
excited on former occasions at the same time. 

Now, since any given object, event, or idea, has been asso- 
ciated with many different things in the past, the general law 
of contiguity is not specific enough to explain why one, rather 
than another of these past associates is recalled. We may 
narrow the problem by saying that the idea which is most 
closely associated will be recalled, or in neurological terms, 
the liability of the given mental content to bring to con- 
sciousness one rather than another of its past associates is 
determined by the permeabihty of the brain pathways con- 
necting the brain centres. The neural impulse will follow 
the most permeable pathway. But to say that the most 
closely associated idea will be recalled is proceeding in a cir- 
cle, unless we can describe the conditions which determine 
the "closeness of association." We have touched upon this 
point in discussing associative recall in memory. We found 
that the operation of the law of association is modified by 
several conditions. For instance, the closeness of associa- 
tion may be determined by any one, or by several of the fol- 
lowing conditions: Recency, frequency, and vividness of the 
associated experiences; the context of thought in the mind 
at the time, and the dominant plan or purpose uppermost in 
the mind. While these conditions determine the direction of 
associative recall, the general fact remains that any given 
mental content always recalls something that has been for- 
merly experienced with it. This is the law of contiguity. 

Similarity. — Now, it may be objected that the so-called 
association by similarity is an exception to the law of con- 
tiguity — that an idea is often recalled because it is similar to 
something we perceive or to something that we may be think- 
ing of at the time. And, further, it may be said that it is a 
common occurrence to have some presentation or idea in the 
mind call up an idea which has never been experienced pre- 



286 PSYCHOLOGY 

viously with it. For example, I may meet a stranger whom 
I have never seen before and immediately I think of a friend. 
Here apparently is a case of recall where the mental contents 
have never been experienced together before. To explain 
such cases, the law of similarity has been evoked. And so it 
is said that the stranger reminds me of my friend because of 
the similarity existing between them. If^ however, we wish 
to explain psychologically why I thought of my friend when 
J saw the stranger, we could make no greater blunder than to 
assign similarity as the cause of the recall, for the similarity 
appears in my mind only after the recall has taken place. 
Instead of the sequence: (i) sight of the stranger, (2) con- 
sciousness of similarity to a friend, (3) thought of my friend, 
what we really have is: (i) sight of the stranger, (2) thought 
of my friend, (3) consciousness of the similarity. It is evi- 
dent that similarity arises only when the two terms compared 
are already in consciousness. But what we are seeking is 
some principle to explain why, given the first term, the 
second term appears. If we analyze the situation more 
closely, we shall see that this principle is the principle of con- 
tiguity after all. While the stranger as a total experience has 
never been associated with my friend, some part of him has. 
It may be the shape of his nose which is identical with that 
of my friend's. This particular shape of nose is a part of 
my friend's make-up which I have experienced in connection 
with all his other characteristics many times. So when I 
meet this feature of my friend in the stranger it recalls its 
former associates. It is plain that what occurs in cases of 
so-called association by similarity is that some feature of the 
present object attracts the attention, and "breaking away 
from its immediate associates, gathers to itself certain of its 
former associates which combine therewith to form the new 
object of thought."^ Judd^ uses the following diagram to 
illustrate association by similarity. 

^ James: "Principles of Psychology." 
2 " Psychology," p. 235. 



ASSOCIATION 



287 




^-f 



\ 



V 



Now, while we may say that any experience tends to call 
up similar experiences, we cannot, however, explain the recall 
psychologically by the principle of similarity. Therefore the 
law of association by similarity holds only as a statement of 
fact and breaks down as a psychological explanation of asso- 
ciation. It is true that sim- 
ilars recall similars,^ but it 
is not the consciousness of 
their similarity that brings 
about the recall. 

It is plain that when we 
perceive similar things the 
fact that they are similar 
attracts attention. For this 
reason they become associ- 
ated, and afterward the one 
will recall the other, because 
of the principle of contigu- 
ity. Similarity is therefore 
one of the principles or con- 
ditions for the formation of 
associations, but is not the 
explanation of associative 
recall. Any relation between things or ideas serves to at- 
tract the attention and, consequently, becomes the condition 
for the formation of associations. The relation of contrast, 
cause and effect, and the spatial and temporal relations, to- 
gether with similarity, are favorable conditions for associative 

^ We might even say that objects and events are recalled because they are 
similar to objects and events perceived or thought of. But when making such 
a statement, we must understand that we are making physical and not psycho- 
logical descriptions. I might say that it was because my friend is similar to 
the stranger that I think of him. This, of course, is true in so far as I am 
merely pointing out physical traits. It is because the two physical objects have 
the same character that the consciousness of the one is followed by the con- 
sciousness of the other, but this is quite different from saying that the con- 
sciousness of the one is followed by the consciousness of the other because of 
the consciousness of the similarity. 



Fig. 70. — To apply this figure to the 
case cited: The circle A represents 
a single feature (the shape of the 
stranger's nose); h, b, b, etc., repre- 
sent his other features. In my past 
experiences A has been a part of 
another system (the features of my 
friend). When A attracts my atten- 
tion, it breaks away from its present 
b, b, b, etc., and revives its old asso- 
ciates, c, c, c, etc. 



288 PSYCHOLOGY 

formation. They serve to hold mental states together in the 
focus of attention until the associative connections are formed. 
But the psychological conditions present during the formation 
of associations may not be present during recall. I may, 
therefore, be attracted to two objects or events because they 
are similar, or because one contrasts with the other, or because 
one is the cause or the effect of the other. But during the 
process of recall these relations do not enter into conscious- 
ness. 

We are, therefore, brought back to the law of contiguity 
as the law of association. Even this law does not explain 
associative recall psychologically. Psychologically, it is only 
a statement of facts. There is no psychological reason why 
mental states that occur together should be recalled together. 
The real reason will be found in the neural processes back of 
the mental states. 

Partial and Total Recall. — There is then no difference 
of kind between the so-called associations by similarity and 
associations by contiguity. Both make use of the same prin- 
ciple of recall — contiguity of experiences. There is, how- 
ever, an important distinction. In one the contiguity is hid- 
den and in the other it is superficial and plainly evident to 
observation. When a given experience as a whole calls up 
experiences that have been associated with it, the connection 
is evident, but when only part of a given experience is active 
in bringing up its past associates, the connection is hidden. 
In the latter case, the given experience is analyzed or broken 
up into constituent elements, one of which has been connected 
with some former experience and for this reason calls it up. 
In the former case the given experience acts as a whole and 
therefore calls up only those experiences which have been 
associated with it in its totality. The so-called "association 
by contiguity" is therefore very much limited in scope. The 
distinction is the distinction that we have already made be- 
tween partial and total recall. Association by similarity is 
simply a case of partial recall and occurs when the present 



ASSOCIATION 289 

contents of consciousness are analyzed and evaluated and the 
pertinent elements used as connecting-links for the next idea. 
Not only are the threads of thought multiplied many times 
in this form of associative recall, but the subtle and delicate 
identities of thought are brought to light. This type of recall 
characterizes the great thinker. Hamlet's soliloquy furnishes 
an excellent illustration of the subtle and hidden association 
of ideas. On the other hand, mere surface contiguity calls out 
trains of mechanical associations. This form of recall — total 
recall^ — is illustrated on page 250. 

Falsification of Association. — Where associative connec- 
tions are not firmly fixed, suggestions given by others may 
falsify the nature of the associations. Such falsification of 
association is especially manifest in children when they are- 
being questioned about actual events which they have wit- 
nessed. If the questions have suggestions in them, the force 
of the suggestions may modify the actual connections made 
in the child's mind, so that he is unable to give a correct 
report of what happened. Persons of weakened mentality or 
even the normal individual when fatigued or excited during 
long examinations may, by skilfully arranged questions, be 
led to give false testimony in court. In certain cases, ques- 
tions which presuppose a certain answer — leading questions — ■ 
or questions which demand the answer which they suggest, 
will actually set up associative connections in the mind of the 
witness, causing him to give false testimony. We have al- 
ready referred to this in our treatment of memory. Those 
who wish a discussion of this phase of the subject may read 
Miinsterberg's "On the Witness Stand," or Whipple's article 
"The Observer as Reported: A Survey of the Psychology of 



' Usually three degrees of activity in recall are distinguished: (i) Total 
recall, (2) partial recall, and (3) focal recall. Total recall embraces those cases 
where the whole of a present thought is active in recalling the next thought, 
partial recall where a part only, and focal recall where some single element or 
feature is active JB recall. Focal recall is, however, simply an extreme case of 
partial recall, . 



290 PSYCHOLOGY 

Testimony."! An excellent German work treating of this 
subject is Stern's "Beitrage zur Psychologic der Aussage." 

Association Tests. — Individual differences in the character 
and rapidity of associations may be studied by means of 
very simple association tests. In general, the more nearly 
alike the surroundings and past life of individuals, the more 
their associations will be alike. For instance, if we should 
give the same list of stimulus words to members of the same 
family, asking each to respond with the first thought that 
comes to mind when he hears the stimulus word, we should 
find a striking similarity in the character of their associations. 
This is to be expected from the nature of associative connec- 
tions. 

There are several forms of association tests. We may 
ask the subject to pronounce a large number of words just as 
rapidly as he can think of them. He then starts with any 
word he wishes and pronounces the words as fast as they arise 
in his mind until stopped by the experimenter, who has noted 
down the words and recorded the time of the associations. 
Such associations are termed (i) uncontrolled associations. Or 
we may place a restriction on the character of the associa- 
tions to be given, in which case the associations are termed 
(2) controlled associations. Three forms of the controlled as- 
sociations have been used very widely: {a) Part-whole, {h) 
genus-species, and (c) opposites. In the part-whole test, a 
list of stimulus words, printed on a slip of paper, is handed to 
the subject who has been instructed to name the whole thing 
of which each word is a part. The total time required to 
make the associations is recorded together with the responses. 
Thus, if a stimulus word is "door," the subject must respond 
with the name of something of which "door" is a part, as 
"house" or "barn" or "building." 

In the genus-species test, the procedure is the same, ex- 
cept that the subject is required to respond to each stimulus 
word by the name of something which belongs in the class 

^Psychological Bulletin, vol. VI, pp. 153-170, May, 1909. 



ASSOCIATION 291 

indicated by it. For example, if the word "tree" is given, 
the response must be some kind of tree, "maple- tree," or 
"apple-tree" or "oak-tree," etc. 

The opposite-test requires that a word which means just 
the opposite of the stimulus word be given. To the word 
"bad" the subject must respond by the word "good," to 
"sane"— "insane," to "high"— "low," and so on. The 
number of stimulus words may be varied at will, but in each 
case the time and the character of the responses must be re- 
corded. In the part-whole, genus-species and opposites, the 
associative responses are controlled or restricted by the set 
of the mind given by the instructions just before the test. 
In the uncontrolled associations there is no such restriction. 

The associations are still uncontrolled when the subject 
is given a list of stimulus words and he responds with any 
word that comes to his mind. The experimental study of 
associative connections may be carried on for a number of 
purposes: To investigate the individual differences in the 
thought content and thought processes as conditioned by 
sex, age, training; to determine the effect of fatigue, drugs, 
etc., on the associative recall; to diagnose abnormal mental 
disturbances and to detect hidden mental tendencies and 
wishes or intentionally withheld information.^ 

Since the formation of associations depends upon original 
experiences, it follows that the character of associative con- 
nections is a clew to the nature of the original experience. If 
ideas call up the ideas which have been connected with them, 
one's past must necessarily be revealed by the character of 
his ideas. If we should ask a number of persons to give the 
first idea that comes into mind when a stimulus word is pro- 
nounced, their different associations would, in most cases, 
reflect some feature of their past. For instance, in a list of 
stimulus words given to a class in psychology was the word 
"Becky." Eight members of the class responded to the 

1 For a description of association tests, see Whipple's "Manual of Mental 
and Physical Tests," 2d ed., pp. 409-455. 



292 PSYCHOLOGY 

word by "Grand," three by "Frances Starr," and the rest 
by scattered associations. It turned out that twelve mem- 
bers of the class had the week before witnessed at the Grand 
Opiera House a play entitled "The Case of Becky," in which 
Frances Starr played the title role. Of the twelve, all but 
one indicated by their associations the fact that they had 
seen this play. 

James quotes an anecdote from Professor H. Stein thai "^ 
which illustrates the fact that the character of our associa- 
tions are clews to our past. The substance of the anecdote 
is as follows: Six strangers found themselves in the compart- 
ment of a railway-carriage. One of the party undertook to 
name the occupation of each member of the party upon the 
condition that each answer a simple question. They all 
agreed, whereupon he wrote a question upon five slips of 
paper and gave one to each of his companions with the re- 
quest to write the answer below. When the leaves were 
returned, he read the answers and without hesitation said to 
the first, "You are a man of science"; to the second, "You 
are a soldier"; to the third, "You are a philologer"; to the 
fourth, "You are a journalist"; to the fifth, "You are a 
farmer." All admitted that he was right. When the stranger 
left the railway-carriage they compared notes and discovered 
that he had written the same question upon each slip of 
paper. It was: "What being destroys what it has itself 
brought forth?" The naturalist had answered, "Vital 
force"; the soldier, "War"; the philologist, "Kronos"; the 
journalist, "Revolution"; and the farmer, "A boar." 

We may not only study the character of association, but 
we may measure the time required to recall an association 
word. When a stimulus word is pronounced, it requires a 
certain length of time before the subject can think of an 
association word. If the word "day" is given, the subject 
may respond with the word "night." If we measure the 
time between the giving of the stimulus word and the re- 
^ "Einleitung in die Psychologic u. Sprachwissenschaft," p.. 166. 



ASSOCIATION 293 

sponse, we shall find that the association time varies for 
normar associations from one to two seconds. But under 
certain conditions there is a marked lengthening of the time. 
If the stimulus word arouses an emotional complex, or if the 
subject does not give the first association for fear of "giving 
himself away," and hunts for another association, the asso- 
ciation time is lengthened. Therefore, both the character 
of an association and the time required to form the associa- 
tion are significant in detecting past experiences. To illus- 
trate: The following test was made upon four students in 
psychology for tHe purpose of detecting which one of the 
four had read a certain article in the morning paper, which 
only one had seen. The procedure was as follows: The foiir 
students were left alone in a room. One of them read the 
following article, but which one the instructor did not know. 

SPOT ON MONUMENT 

Causes Washington People to Believe "Human Fly" is Busy 

Washington, May 7. — Rumors that a New York "human fly" 
who has been scaling the office buildings here was climbing the side 
of the 555-foot Washington Monument gave the city no end of ex- 
citement to-day. Some one suddenly discovered a black spot on the 
side of the shaft about 150 feet from the top, and then the report 
started. 

Hundreds of people rushed to the monument grounds. Along 
Pennsylvania Avenue crowds collected at every corner, and windows 
and doorways rapidly filled with people. Investigators said that the 
supposed spot was only a spot left by the rain. 

The War Department, which controls the monument, was be- 
sieged with telephone calls. Nearly three hours after the first ex- 
planations a telephone message from the Capitol said the legislators 
were watching the spot through opera-glasses and were convinced 
that it moved occasionally. 

A list of fifteen stimulus words (the words in column (i) 
of Table I), in which six "dangerous" words were placed — 
opera, spot, human, climb, fly, Washington — was prepared. 
The four students were then given this list separately. Their 



294 



PSYCHOLOGY 



responses and association time were taken and are given in 
the table. The subjects are designated by the letters B, M, 
W, and C. B gave the responses in column (2), M in column 
(3)) W in column (4) and C in column (5). 



TABLE I 



STIMULUS WORDS 


RESPONSES 


(I) 


(2)B 


(3)M 


(4)W 


(S)C 


I. Summer 


winter i 


winter i 


winter i 


winter i 


2. Opera* 


play I 


singing i 


hcAise 2 


music I 


3- Day 


night I 


night I 


night I 


night I 


4. Spot* 


blotch I 


black 2 


board i 


piece I 


5. Table 


desk I 


chair i 


legs I 


cover I 


6. Human* 


man [5] 


life 4 


men i 


"divine 4 


7. Come 


go I 


go I 


go 2 


go 2 


8. Climb* 


mountain [3] 


crawl I 


tree i 


tree 2 


9. Window 


door I 


shutter 2 


glass I 


cushion i 


10. See 


land 3 


bay 2 


water i 


ocean 2 


II. Tie 


collar 2 


red 2 


road I 


knot 2 


12. Fly* 


wasp [4] 


bird I 


wings I 


bugs I 


13. Book 


ledger 2 


paper 2 


leaves i 




14. Washington* 


Jefierson [3] 


Lincoln i 


capitol I 


D.c' I 


15. Sour 


sweet I 


sweet 2 


bitter i 


sweet r 



The dangerous words are marked in the table with an 
asterisk. The numerals in columns (2), (3), (4), and (5) 
represent in seconds the association times for each response. 
The time was taken with an ordinary stop-watch, since the 
test was made only for rough demonstration purposes. For 
more exact laboratory work, the time may be taken in hun- 
dredths of seconds. 

Subject B was correctly designated as the guilty person 
by the results of the tests. He passed two of the dangerous 
words without lengthening the time of reaction. But when 
he came to "human," his first association was "fly," but 
since that would have indicated his acquaintance with the 
article just read, he did not give it. It required several 
seconds to change the association word to "man." Therefore 
his association became "blocked." Sometimes it occurs (not 



ASSOCIATION 295 

shown in this test) that the blocking of an association will 
be delayed and appear in the associations immediately fol- 
lowing a dangerous word which the subject passes success- 
fully. This takes place where there is more at stake than in 
the demonstration test just given. What happens in such 
cases is that an emotional disturbance started by the danger- 
ous word requires time to develop, and therefore shows its 
effect in later associations. 

Attempts have been made to apply association tests to 
suspected criminals for the purpose of detecting their fa- 
miliarity with places and events connected with crimes.^ 
The association method has also been used in the diagnosis 
of cases of hysteria and neurasthenia. It is supposed that 
such mental affections are due to certain past experiences ot 
highly emotional character which have been repressed and 
submerged in consciousness. The patient either desires not 
to give expression to, or has half-forgotten these experiences. 
In either case, they are nevertheless constant sources of men- 
tal disturbances. By giving long lists of words properly 
selected, the physician is able to detect those which show 
abnormal associations, and so indicate that they have 
"tapped" the emotional complexes in the patient's mind. 
In this way it is often possible to discover the nature of the 
mental disturbances — to uncover the experiences which have 
been disturbing the mental equilibrium of the patient. Past 
experiences which lie at the bottom of hidden and unex- 
pressed desires, secret worries, and divergent or antagonistic 
tendencies which are the beginning of mental dissociation are 
brought to the surface of consciousness by arousing sup- 
pressed associations. Such associations may reach back to 
the early life of the patient, even to the years preceding 
adolescence. It is here that Freud has rendered important 
service to abnormal psychology through the method of psy- 

* See Miinsterberg's "On the Witness Stand"; also lectures given by Jung 
at Clark University, on "The Association Method," American Journal of Psy- 
chology, XXI, 1910, pp. 219-270. 



296 PSYCHOLOGY 

cho-analysis. This method supplements the association 
method by seeking through a series of questions to draw out 
the patient and induce him to give full expression to the sup- 
pressed or half-forgotten experiences, which nevertheless pre- 
serve subconscious associative connections with the present 
conscious life. When these associative connections are re- 
awakened, the unity and equilibrium of consciousness is 
restored. 

An interesting phase of Freud's theory is the importance 
he attaches to dreams as clews to hidden experiences, sup- 
pressed desires, and wishes. He believes that in many cases 
dreams are symbols of the wishes which we do not allow 
ourselves to express in waking moments. A careful analysis 
of our dreams will often enable us to determine what these 
suppressed wishes are. 

The work of Jung and Freud has done much to demon- 
strate the fact that associative connections once formed are 
not entirely lost, even though we may not under normal 
conditions be able to recall them. The threads of past asso- 
ciative bonds may remain and exert a much more powerful 
influence on our mental life than we ordinarily suppose. Ex- 
periences which we have forgotten may play a part in deter- 
mining the course of our thought and action. No matter 
how much the individual may wish to shake loose the bonds 
which connect him with his past experiences, or how success- 
ful he has been in putting them out of his thoughts, their 
impress has been left upon him, and is, therefore, a compo- 
nent element in the underlying strata of his character. 

Physiological Basis of Association. — We may easily form 
some conception of the neural mechanism involved in the 
associations which are set up between presentations and the 
motor responses which we make to them. In such cases, the 
nervous impulses aroused in the sensory centre discharge into 
motor centres and pathways. We have already seen that 
this discharge of sensory centres into motor pathways is a 
general characteristic of the central nervous system. In a 



ASSOCIATION 297 

large number of cases, the particular motor response that 
becomes associated with a given presentation is one that has 
been gradually selected and stamped in because of its fitness 
in adjusting the individual to the presented situation. The 
particular motor response is, therefore, the successful one of 
the many responses that were, from the beginning, natively 
associated with the given presentation. Such is the method 
of learning motor responses by trial and error. 

But when we ask how one presentation comes to be asso- 
ciated with another presentation, as is the case in association 
by contiguity, the problem set for physiological psychology is 
much more difficult than is the case where one term of the 
association is a motor reaction. When, for instance, the 
child sees a horse for the first time and hears the word pro- 
nounced, how does the visual centre, corresponding to the 
sight of the horse, come to be connected with the auditory 
centre, corresponding to the sound of the word, so that after- 
ward the one arouses the other? In the first instance, each 
centre is aroused independently of the other. Is the mere 
fact that they are active at the same time sufficient explana- 
tion for the fact that a neural pathway is opened between 
the centres, so that when afterward the child sees a horse, 
the word comes to the mind, or when he hears the word the 
visual image of the horse comes to mind ? At present, physi- 
ology cannot answer the question, so we shall have to accept 
the most reasonable theory. McDougall^ proposes the drain- 
age theory to account for the formation of neural connections. 
According to this theory, when the child sees the horse, his 
visual centre is excited, then he hears the word "horse" and 
his auditory centre is excited. The attention shifts from the 
visual appearance of the horse to the sound of the word. 
Accordingly, the activity aroused in the visual centre is 
drained off by the auditory centre. Thus a neural pathway 
between the two centres is formed. 

1 "Physiological Psychology," p. 126. 



298 PSYCHOLOGY 

Ladd and Woodworth^ are of the opinion that the drain- 
age theory does not explain all cases of association by con- 
tiguity and, further, that in some cases where complete drain- 
age between centres could very well take place, no associative 
connections are formed. Such cases are found, for instance, 
in the shifting of the attention in the staircase or bent card- 
board figures. Here attention shifts from one aspect of the 
figure to the other, affording a splendid opportunity for the 
drainage of one centre by the other. Yet there is, so say 
these authors, no evidence of the association between the 
two perceptions of such figures. They agree that in the for- 
mation of associative connections nerve currents must pass 
between the different centres involved. But it is not the 
mere drainage of one centre by the other that sets up the 
associative connections. It is not the shifting of attention, 
but the movement of attention with anticipation or expec- 
tancy of something to come, with a lingering of what has 
just gone. In neural terms, this expectancy corresponds to 
a damming up of energy in the first centre until the expected 
stimulus comes; then it discharges into the centre aroused 
by the stimulus. Illustrating the formation of association 
between the visual appearance of a new acquaintance and 
his name, these authorities say: "If one says, for example, 
'Let me present Mr. A,' the nervous energy aroused by the 
sight of the man is perhaps held in check till the name is 
spoken, and then discharged into the centre aroused by the 
auditory stimulus which, on account of its being aroused by 
this stimulus, would the more readily attract other nerve- 
currents having a partially open path into it. Such a condi- 
tion would account, also, for the special clearness with which 
an expected stimulus is perceived." 

^ "Elements of Physiological Psychology," pp. 617-625. 



CHAPTER XIII 
CONCEPTION 

Thinking. — In perception and imagination we have treated 
only that aspect of consciousness which is concerned with 
separate and particular things and events. But conscious- 
ness includes more than the perception or the imagination 
of discrete things. We are never aware of an object with- 
out involving more than the object itself. An object is 
always presented in some context — in some relation to other 
things. The pen that I now see is not just a pen. It is a 
pen writing — my pen — the pen that / bought yesterday — a 
pen made of steel — etc. I am more or less conscious of these 
relations when I image or perceive the pen. I not only see 
the book, but I am conscious of it on the table before me — as 
belonging to my friend — as written by Holmes. The conscious- 
ness of these relations is just as much a mental content as 
the consciousness of the presented object. It is the con- 
sciousness of relationship which binds the discrete elements 
of our mental life together. Sometimes our attention is 
fixed chiefly upon the sensory appearance of the object and 
sometimes upon the relations. When we attend primarily 
to the relations between things, we employ a phase of con- 
sciousness which we have not yet discussed. This form of 
conscious activity is thinking. 

Thinking is the manipulation of data given in sensation, 
perception, and imagination in such a way that the relation- 
ships existing between things are actively attended to. 

The consciousness of relationship is implicitly present in 
all forms of consciousness, save perhaps in the so-called pure 
sensations. Perception, for instance, cannot take place with- 
out recognition of the object perceived and recognition is 

299 



300 PSYCHOLOGY 

the implicit consciousness of the relation of sameness or 
identity. There is also present in the perception of an ob- 
ject, the relations which the object bears to other things. 
Sometimes the emphasis is placed upon the sensory presen- 
tation of the object, while relationships occupy the back- 
ground of consciousness. In thinking, on the other hand, 
the consciousness of relationship comes to the front and is 
made the bridge over which we pass from one discrete ele- 
ment of thought to another. 

Can we be conscious of things without their relations? 
Theoretically, the "pure sensations" (the hypothetical first 
sensations), if they exist, involve no consciousness of relation- 
ship. One might suppose that the baby's first consciousness 
is a mass of vague, unrecognized experiences — that his first 
sensations of cold and warmth, of pressure and taste, are 
bare disconnected mental flashes of sensory contents not 
related in any way in its consciousness. But, even here, our 
earliest observation of the child shows that he does relate 
his experiences. When he sees his mother, nurse, or bottle, 
there are unmistakable signs that he experiences, although 
perhaps dimly, a feeling of familiarity which may be charac- 
terized by ' ' this - is - like - something - 1 - have - experienced - be- 
fore." Whether we look upon this primitive and simple 
relational experience as a rudimentary form of thinking or 
not, it cannot be doubted that the thinking process is founded 
in this faint awareness of sameness or identity. James says: 
"A polyp would be a conceptual thinker if a feeling of 
'Hollo! thingumbob again!' ever flitted through its mind." 

Thought then adds to the bare perception of individual 
things the consciousness of relations existing between them, 
thus organizing and unifying and rendering intelligible what 
would otherwise remain isolated and chaotic in conscious- 
ness. There are three aspects of the thinking process — con- 
ception, judgment, and inference. These aspects are inti- 
mately related and interwoven and really belong together. 
We shall, however, treat them in separate chapters. 



CONCEPTION 301 

The Concept. — As we said, in perception, imagination, and 
memory, consciousness is concerned with individual and 
particular things. We perceive, or image, or remember this 
particular object, or that particular event. In short, in 
perception and imagination we are always dealing with a 
world of particular and concrete experiences. We have, for 
instance, known a number of individual horses and we can 
form an image of any one of them, more or less perfectly. 
If we were obliged, however, to image all these individual 
horses when we wish to think or speak of them, we could 
make very little progress in thinking or in communicating 
our ideas to others. Such a method would be a very cum- 
bersome way of making use of past experiences. If we were 
content, when thinking or speaking of horses, with the image 
of a single horse, the thought would be a poverty-stricken 
and fragmentary representation of what we really know of 
horses, and anything we could say about them would be 
very much limited in scope. 

What we need for the purposes of thought and the com- 
munication of knowledge is some form of consciousness which 
will consolidate the essential elements of our past experiences 
with similar objects into a single mental content which com- 
prehends all of them at once. Happily, this need is supplied 
in the concept. The concept is the mental state which com- 
prehends a number of particulars possessing a common ele- 
ment or group of qualities in a single mental content. For 
instance, the concept horse refers to all horses and attaches 
a common group of qualities to each member of the class. 
The concept John Jones refers to all the different particular 
aspects of an individual. The concept is therefore general 
and not particular in its reference. It refers to all the mem- 
bers of a class, or to all the different aspects of a single object 
and emphasizes a common or universal quality which is 
taken to be the same throughout a variety of instances. 

The conscious states which comprise our thoughts of 
horse, wood, dog, tree, London, John Jones, truth, honesty, 



302 PSYCHOLOGY 

etc., are concepts. We mean by horse any horse whatso- 
ever, or the common qualities of all horses; by London, all 
its different parts and aspects; by honesty, the essential 
character of all honest acts; and not this horse, or this aspect 
of London, or this concrete act of honesty. 

The Formation of the Concept.— The formation of the 
concept involves, either explicitly or implicitly, the process 
of abstraction and generalization. After the reflective proc- 
esses have developed, we may reform our old concepts or 
form new ones according to logical laws. We may then, 
with the avowed purpose of forming a correct general no- 
tion, observe each individual case of a class of objects, ana- 
lyze each into its elementary qualities, compare the different 
cases, abstract the common qualities, and then generalize 
them into a concept. This is the logical formula for getting 
at the universal character of things. But nearly all our 
concepts grow up unreflectively out of our every-day experi- 
ence with things and do not, therefore, follow this formula. 
Concepts begin in the hazy ideas of childhood and only 
slowly assume their present character. In the unreflective 
formation of concepts the abstraction and generalization of 
common qualities of a class of Uke objects is not the result 
of an explicit reflective process, but is implicitly impressed 
upon us chiefly because the individual objects of any given 
class call out the same reactions. The way we react to 
individual objects is the most potent factor in our early 
classification and definition of things. Because we react in 
the same way to different individuals of the same class, we 
come to think of them in the same way — to discover and 
emphasize the same qualities in them. For instance, we 
react in the same way to all individual chairs, tables, horses, 
etc., and so come to think of each class in the same terms. 
At first children define entirely in terms of use, or we may 
say in terms of their characteristic reactions to the things 
defined. Thus, chair is "something to sit on," table is 
"something to eat on," horse is "something to ride or drivQ," 



CONCEPTION 303 

Their first notions are, therefore, determined by their reac- 
tions. 

The Psychological and the Scientific Concepts. — The con- 
cepts which have grown up gradually in our perceptual and 
unreflective experience are called psychological concepts, to 
distinguish them from the concepts which are the result of 
reflective thought, in which the processes of comparison, 
abstraction, and generalization are purposely instituted in 
order to determine the exact nature of things. Concepts 
formed in this way are called logical or scientific concepts. 
They are termed ^^ logical^' because they are the product of 
a more or less formal logical procedure, and "scientific^' be- 
cause they are attempts at exact formulation and definition 
of meanings. 

Very few people can satisfactorily define water, air, table, 
truth, because they have never subjected their experiences 
with them to reflective observation and analysis. They are 
unable to point out the universal and distinguishing qualities 
of these common things. Yet we all have a good working 
notion of them, which has been gained in every-day experi- 
ence, and which serves our practical purposes. The logical 
concepts are, however, superior instruments of thought and 
action. The man who has carefully and logically thought 
out the nature of things and has explicitly formulated their 
meanings so that he knows exactly what they include is 
better able to control them. Any farmer has a practical 
notion of trees. His concepts of elm, oak, hickory, ash have 
been gained through an extended practical experience, yet 
he is not able to take a position in the government horticul- 
tural service. His concepts of apple, peach, and plum are 
as complete as ordinary perceptual experiences can make 
them, yet he cannot compete with the student from the hor- 
ticultural department of the College of Agriculture in han- 
dling an orchard. 

The psychological concept, however, is the basis — the 
first stage in the development of the logical concept. Unre- 



304 PSYCHOLOGY 

flective generalization gives us our first notions of things. 
Reflective thought refines and defines them into logical con- 
cepts. 

The General and the Individual Concept. — If we consider 
the intrinsic nature of the concept instead of the manner of 
its formation, we find two forms: the general and the indi- 
vidual concept. The general concept is that mental state 
which refers to all the members of a class of objects having 
a common quality or group of qualities. Thus, "man" is a 
general concept. We mean by man every member of the 
class and to each member we attribute a universal group of 
quahties. 

The individual concept is that mental state which refers 
to all the different aspects of a single object. Thus, the 
mental state which corresponds to "John Jones," is an indi- 
vidual concept. John Jones, as an actual, concrete exis- 
tence, has many different states, qualities, and activities. I 
have, for instance, met him in society, in business, on the 
golf-links, in the club, etc. No single image of John Jones 
can represent him in all his totality. The concept, "John 
Jones," on the other hand, consolidates all his states, quali- 
ties, and activities, as I have known them, into a single men- 
tal content. When I think John Jones, I do not mean John 
Jones in particular, but John Jones in all his aspects. Just 
as in the general concept "man," I mean all the different 
individuals of a class, so in the individual concept John 
Jones, I mean all the different aspects of his existence. By 
the general concept we think the same quality in a number 
of different individuals; by the individual concept, we think 
the same individual in a number of different qualities. 

The individual concept involves abstraction and gener- 
alization quite as truly as the general concept. In forming 
the concept John Jones, we isolate the qualities which be- 
long to John Jones and mark them off as distinct from those 
of other men. We generalize when we think John Jones in 
all these different aspects. 



CONCEPTION 305 

The Analysis of the Concept. — So far we have spoken only 
of that which the concept does, its functional aspect. We 
have said that it refers to all the members of a class, or to 
all the characteristics of an individual. We must now in- 
quire into the nature of the concept itself, its structural 
aspect. Of what kind of "conscious stuff" is the concept 
made? The answer to this question will show us how a 
single mental state "refers to," "comprehends," or "con- 
solidates" a number of particular objects and particular 
qualities into a mental unity. 

If we examine carefully the content of any concept, we 
shall find two constituent elements in it: (i) The image and 
(2) the consciousness of meaning. For instance, at the mo- 
ment I think "horse," the content of my consciousness is 
made up of an image of some kind and a definite core of 
*' horse meanings." 

The Image. — The image may be either concrete or verbal. 
In the case cited, the image may be either the concrete visual 
image of some particular horse, or the visual, motor, or 
auditory image of the word "horse." Any one of these 
images may serve as a means of attachment for the meaning 
implied in the concept. When I think of horses in general, 
I sometimes find myself entertaining a rather indefinite, 
hazy, visual image of a horse. Sometimes the sound of the 
word "horse," together with the feelings of enunciation, as 
though I were about to pronounce the word, "horse," arise 
in my mind. Now, in the first case, the image is a copy 
image. In the second case, the word image is purely sym- 
bolic. It serves as a symbol of the things I am thinking 
about. It is safe to say that the word image is most com- 
monly used in the concept. 

. In cases where the visual image of some particular horse 
arises in my mind, I do not intend or mean the particular 
horse imaged, but the whole class of horses. It is perfectly 
possible for concrete images to function in this way. In fact, 
all imagery must, in order to function in a concept, be sym- 



3o6 PSYCHOLOGY 

bolic, i. e., stand for or signify something beyond itself. No 
image can copy all the varying sizes, forms, and colors of all 
the individual horses I have known. Nor is it necessary 
for the image to be like the things it stands for, any more 
than the sign of a grocery store needs to be like the store 
itself. An image may stand for something beyond itself, 
even though it is not like it. 

The mistaken assumption that images must resemble the 
things they signify has led some writers to deny the possibility 
of general ideas. They assert that only ideas of individual 
and particular things are possible, for it is impossible to 
form a general image. Locke contended that a general idea 
of a triangle is impossible, because no single image could pic- 
ture all forms of triangles. But he neglected the fact that 
the image of any particular triangle may mean or signify all 
other triangles. 

Certain psychologists, still believing that the image must 
correspond to the thing it signifies, proposed the theory of 
the generic image. The generic image is supposed to be a 
"general image" — a composite of all the characteristics of 
the particular individuals in a class — a composite photo- 
graph, so to speak. Accordingly, the generic image is 
thought to have a "distinct and salient centre or core cor- 
responding to the common characteristics of a class, together 
with a vague and inconstant margin corresponding to the 
variable characters of the individuals composing the class." ^ 

The generic image, therefore, is a form of the copy image, 
but as such it is wholly inadequate, as we have pointed out. 
What would be the character of the generic image of color? 
The writer has never been able to observe a generic image 
in his own consciousness. Hazy, sketchy, and indistinct 
images of some particular object, or images constructed out 
of the re-presentations of parts of different objects of the 
same class, he has, but such images are not generic images. 

^ Baldwin's "Dictionary of Philosophy and Psychology," article on Generic 
Image. 



CONCEPTION 307 

After all, the generic image is not necessary. Any image 
can be the bearer of meaning. Most of the images we use 
in thinking are verbal images and they bear no resemblance 
to the things they stand for. We have already seen in the 
chapter on imagination that there is an increasing tendency 
to give up concrete copy images and use word images instead. 

Not only images, but also perceptions may serve to sig- 
nify meaning. The perception of a certain shell may in the 
geologist's mind signify the characteristics of a whole geo- 
logical age, provided his attention is centred on its meaning 
and not on its sensory appearance. 

Consciousness of Meaning. — ^The important part of the 
concept is consciousness of meaning. When we see or hear 
the words "chair," "table," "book," we understand what 
they mean, although we may not consciously re-present any 
one of the concrete things named. The content of con- 
sciousness is, in each instance, made up of the word and its 
meaning. If, on the other hand, we should see or hear the 
words "elbat," "koob," "riahc," we do not understand 
them. There is practically no consciousness of meaning, 
nothing but the sensory aspects of the words. 

Whenever an image or percept stands for, signifies, sym- 
bolizes something that is not present as a sensory content, 
the '^standing for/' " signifying, '^ "symbolizing," is conscious- 
ness of meaning. The word "book" arouses a definite group 
of meanings, which are marked off in the mind from all other 
meanings. The word "dog" arouses a different group. 
And so each symbol of meaning turns consciousness in a cer- 
tain direction, and gives an added content to consciousness. 
This content (meaning) cannot be described, for it does not 
exist in sensory terms, but rather in terms of relation. That 
it is a conscious content which gives a determining character 
to the concept may be shown in various ways. For instance, 
suppose I should pronounce the word "bear." Your mind is 
turned immediately toward a class of wild animals. But 
suppose that, while this meaning is hanging in your mind, I 



3o8 PSYCHOLOGY 

add the words "your burdens cheerfully"; you would then 
know that you had aroused the wrong meanings. A mental 
shock, accompanied by the feeling that the animal meaning 
is not appropriate would follow. You would then, while 
the words (''your burdens cheerfully") were still upon my 
lips, change the meaning — turn your mind in the proper 
direction. This experience would be impossible if conscious- 
ness of meaning were not a definite mental content. 

Now, we have already seen that no moment of conscious- 
ness, with the possible exception of the pure sensation, is 
absolutely isolated and free from meaning. All experience 
is interwoven by the threads of relationship. Everything 
experienced suggests the relations it may have to other things 
and to other aspects of its own existence. For instance, the 
momentary perception of one aspect of the penknife (its 
appearance as it lies on the table) means all the other char- 
acteristics of it not now presented, because I recognize the 
knife as the same throughout its different aspects. Or it 
may mean for me all other individual members of its class, 
because I recognize a certain group of characteristics as the 
same in a number of different instances. In the one case, 
the concept is individual and in the other general. The im- 
portant point to be noted is that in either case consciousness 
of meaning is based upon the relations which exist between 
the parts of our conscious life. When attention is directed 
toward the relational connections which a thing or its image 
has, instead of upon the thing itself, we are conscious of 
meanings. The definition and organization of these mean- 
ings into distinct units which mark off classes of objects is 
the formation of the concept. 

The Intension and Extension of Concepts. — The definite 
group of meanings which a thing or term has for us is known 
as its intension. For example, the meanings which are com-i 
prehended by the concept "horse" constitute its intension. 
The use of this meaning to mark off a single group or class: 
of separate objects constitutes the extension of the concept.. 



CONCEPTION 309 

Thus, the application of "horse meaning" to all individual 
members of the class "horse," constitutes the extension of 
the concept. The definition of the concept consists in. set- 
ting out clearly the meanings which are embodied in it, i. e., 
in making its intension explicit. It is plain that as the ex- 
tension of a concept increases, the intension is restricted. 
The intension of general concepts is much more restricted 
than is the case in individual concepts. The meanings which 
we can apply to a number of different individuals are fewer 
than those which we apply to a single individual. 

The Genesis and Development of the Concept. — The be- 
ginning of the concept is laid in perception. Just as soon as 
a presented object begins to suggest qualities and attributes 
not actually presented to the senses, it begins to function as 
a concept. The growth and development of the concept's 
continues just as long as we continue to get new experiences 
from the object. After we have experienced an object many 
times and have come to know its various aspects, any single 
presentation reveals not all of the object as we really know 
it, but a single aspect of it. All its other aspects are either 
ignored and attention given to the object's sensory character 
at the moment, or they are given as meanings. If attention 
is placed upon the presented sensory content, while the mean- 
ings occupy the background of consciousness, the mental 
state is perceptual. But if the presented object itself is a 
secondary consideration and we become intent upon its 
meanings, then the mental state is conceptual.i For in- 
stance, on the mantel in my study there is an old Pompeian 
lamp. If, as I look at it, my consciousness is confined to its 
form and color, the material of which it is made, and the 
figures carved upon it, my consciousness is perceptual. But 
if when I look at it I feel the tug of a hundred thoughts con- 
cerning it and the fated city it represents, striving to rise to 
full consciousness, then the presented object is merely a 
symbol for a whole troop of meanings, and it really functions 
as a concept. If we could follow the development which the 



3IO PSYCHOLOGY 

consciousness of this object has undergone in my mind, we 
should have the history of the development of an individual 
concept. 

Hand in hand with the development of the individual 
concept goes the development of the general concept. We 
not only learn to know a single object in all its various as- 
pects, but we also learn at the same time what character- 
istics are common to all the members of the group to which 
it belongs, and thus we form the general notion. We should 
note that these two processes go on together, that the indi- 
vidual notion and the general notion develop at the same 
time — that as we meet different individuals of the same class 
we discover more and more the particular characteristics of 
any single individual, and as we discover new characteristics 
in the individuals, we learn more about the class as a whole. 

It is sometimes assumed that our general concepts origi- 
nate only as a result of that logical process of thought which 
starts with a number of particular objects, analyzes and com- 
pares them, abstracts the common qualities and generalizes 
them into the concept. The origin of the child's concept of 
lamp would, according to this assumption, first involve the 
acquaintance with a number of individual lamps and require 
that he should then compare, abstract, and generalize before 
he has any notion of lamps in general. This is a false as- 
sumption. What really happens is quite different. In his 
first experiences with a single lamp the child will be attracted 
by some striking characteristic (its light-giving quahty). 
This immediately becomes a general notion which he uses to 
interpret other cases. For instance, he may call the moon 
a lamp. He, therefore, generalizes from the very beginning, 
using what he has gained from his first experience as a stand- 
ard. His notion of particular lamps and his idea of lamps 
in general both start in this limited experience and develop 
gradually as his experience is extended. The young child 
calls all men "papa," or his first sheep "dog," showing that 
he has crude embryonic concepts from the first. But, refer- 



CONCEPTION 311 

ring to the latter illustration, further sheep experience may 
do two things to his concept: (i) It causes him to notice for 
the first time that his own dog has short hair, claws, and a 
long tail, thereby increasing the intension of the concept; 
(2) it restricts the extension of his general concept, since 
afterward he may not include sheep in it. Further modi- 
fication of his concept takes place as he meets other dogs of 
different kinds. His experiences with bird-dogs, hunting- 
dogs, watch-dogs, etc., all modify his general concept, and 
at the same time bring out more definitely the characteristics 
of each individual. It is, therefore, in the process of form- 
ing general notions that the child gains a definite knowledge 
of particular things, and it is his contact with particular 
things that modifies and develops his general notion. 

Now, while it is true that the foundation of knowledge 
must be laid in first-hand experiences with things themselves, 
it is also true that after we have gained a store of meanings 
in this way, we may extend our old concepts and gain new 
ones through creative imagination, when guided by language 
descriptions and definitions. I may, for instance, never have 
seen a zebra or a picture of one. Nevertheless, I may get a 
fairly accurate concept of this animal from my readings or 
from the descriptions given me by another person. Guided 
by oral or written descriptions, I may fill in the sensory de- 
tails by concrete imagination, drawing, of course, upon my 
first-hand experience with similar objects (horses, ponies, 
mules) for the material of my ideal construction. These ex- 
periences are modified and reconstructed into my idea of 
the zebra. Many of our concepts are formed in this way. 
This form of conceptual growth and modification requires a 
higher stage of mental activity than that based upon per- 
ceptual experience. 

Still a higher form of conceptual development and modi- 
fication is found in our more abstract and scientific concepts, 
in the development of which neither perception nor concrete 
imagination plays any important, determining part. Such 



312 PSYCHOLOGY 

concepts consist of relations which we comprehend by means 
of the higher thought processes. Our concepts of infinity, 
law, force, atom, are illustrations. They are developed out 
pi our knowledge of the relations existing between things, 
and which we discover through the processes of judgment 
and reason. 

The concept, then, is the outgrowth of experience, in 
which perceptual and imaginary contact with things and 
the comprehension of relations in judgment and reason are 
prominent factors. 

Language. — ^From the nature of the concept, we can see 
very plainly the need of a system of signs or symbols, to 
which we may attach our meanings. Every concept is a 
group of meanings which requires some tangible sensory con- 
tent to call it up in our mind. We have already seen that 
the concrete image of an object serves in some instances to 
arouse its meanings. We have also noted the tendency in 
thinking to substitute for the concrete image of the object 
the image of the word which stands for the object. And, 
further, not only the image of the word, but also the actual 
perception of it may serve as a symbol of our meanings. 

Language is a system of signs which we use to mark off 
meanings. Every word we use, or see, or hear, or image, is 
a symbol of something, and is, therefore, conceptual in na- 
ture. Thought deals with meanings, and language is the 
instrument of thought — the tool by which we handle mean- 
ings. If I should name in rapid succession a half-dozen 
things in my office: chair, pen, book, desk, door, table, you 
would in each instance understand what I mean — each word 
would arouse a definite set of meanings in your mind without 
the necessity of your forming an image of any one of the 
objects named. In other words, you have entertained a 
number of concepts. The mere presence of these uncon- 
nected concepts in your mind does not, however, constitute 
thinking. But if I should put some of these concepts to- 
gether in such a way that my words express a relation be- 



CONCEPTION 313 

tween them, then thought would be aroused. Thus, I may 
pronounce the words: "The book is on the table near the 
door." Now, the words in themselves are nothing but a 
series of bare sensory sounds — mere symbols. There is noth- 
ing in the sounds that you hear which imitates or in any 
other way gives a clew to the condition which exists in my 
office. The words are merely arbitrary symbols of the mean- 
ings which arise in your mind. And as symbols, it makes 
no difference what they are, so long as we all agree to use 
the same symbol for any given meaning. I might have said 
just as well: "Le livre est sur la table pres de la porte," or 
"Das Buch ist auf dem Tisch nahe der Thiir." I might 
have written the sentence on the blackboard, or I might 
make use of the deaf and dumb alphabet, or if it were possi- 
ble I might convey the thought to you through gestures and 
natural signs. The meaning in all cases would be the same. 
Some of the symbols, however, would be more convenient 
and expeditious than others. And in the last case, the na- 
ture of the symbols would differ in principle from all the 
preceding cases. In trying to make you understand by 
gestures and natural signs, I am necessarily obliged to use 
the primitive method of imitative or concrete imagery in 
arousing the meanings in your mind. I should have to point 
to this book, and that table, and that door in this room, 
and then by gestures try to make you understand the con- 
dition in my office. In all the other instances, the words 
suggest the proper meanings without the necessity of your 
filling in by concrete imagination as you do in this case. 

From the psychological point of view, one of the functions 
of language signs is to arouse meanings, or rather to symbol- 
ize meanings in our own thought processes — to communicate 
ideas to ourselves, so to speak. For it is true that we think 
very largely in terms of words, i. e., we use visual, or audi- 
tory, or motor images of words in thinking. As an instru- 
ment of thought, language signs sort out and preserve our 
meanings. Figuratively, we may say that a word is a pigeon- 



314 PSYCHOLOGY 

hole into which we pack away certain definite meanings 
which we may use later by merely glancing at its number. 

But language has other functions — the communication of 
meanings to others. Each word that I use arouses the 
meanings which you, through your past experiences, have 
attached to it. I may, therefore, direct your thought through 
language signs. As an instrument of communication, lan- 
guage is a social institution. The social aspect of it con- 
tributes very much to the development of conceptual thought. 
Each individual communicates to others the particular mean- 
ings which his experience has given him, so that in the end, 
any given language symbol comes to have a group of mean- 
ings, which is the product not of a single individual, but the 
result of the co-operation of the members of a social group. 
A word when used as a means of communication by several 
individuals becomes a clearing-house of meanings. The re- 
finement, organization, and development of meanings which 
language fixes for us is due largely to social influences. 

The earhest form of language (using the term in its broad- 
est sense) is the language of natural signs, or imitative ges- 
ture. In natural signs, the symbol must have something in 
common with the thing symbolized, as when barking like a 
dog is used to communicate the idea *'dog," or when one 
closes his eyes to signify sleep, or points to the clouds to 
indicate rain, or puts the hollow of his hand to the mouth 
to make known the fact that he is thirsty. It should be 
noted that gestures that merely point out objects are not 
really language signs. For instance, if I point to the clouds 
simply to call your attention to them and nothing more, 
then the pointing and the thing pointed out are not really 
signs. They do not signify anything beyond that which is 
present. A sign or symbol must stand for something beyond 
itself — something not present. It must imply some mean- 
ing in order to function as a language sign. If, however, my 
pointing to the clouds is for the purpose of signifying rain, 
then the act becomes a true symbol. Any gesture or imita- 



CONCEPTION 315 

tive act which symboKzes something not present may be 
considered a language sign."^ 

But natural signs are cumbersome, inconvenient, and 
unmanageable, since they must consist in the reproduction 
of much of the original, sensory content of experience. Only 
by imitating the sensory appearance of things are natural 
signs able to convey an idea of them. This is at times im- 
possible. At best only the simplest and crudest concepts 
and only those not too abstract can be represented by natural 
signs. "To make," says Taylor, "is too abstract an idea 
for the deaf-mute; to show that the tailor makes the coat, 
or that the carpenter makes the table, he would represent 
the tailor sewing the coat, and the carpenter sawing and 
planing the table. It is difficult or impossible to represent 
by natural signs what is common to all kinds of making in 
abstraction from what is specific in this or that kind of mak- 
ing. But if we use a conventional sign, such as the words 
^to make,'' the difficulty disappears."^ 

The first primitive attempts to communicate ideas by 
means of written characters show the same tendency to 
imitate the sensory appearance of the things represented. 
Ideas were communicated by pictures (ideograms). Thus, a 
picture of a horse stood for the idea horse. But here, also, 
the picture is too cumbersome a form and has given way to 
the conventional written word. The picture was found 
hopelessly inadequate for representing concretely all the 
different aspects of an object and, failing in this, the ideo- 
gram became more and more merely a conventional sign or 
symbol. 

It is a significant fact that we find even yet in our highly 
developed conceptual thought, controlled and guided by 
conventional language forms, the old primitive tendency of 
the natural sign-language to imitate in thinking the objects 

^ Stout: "Manual of Psychology," p. 471. 

^Article on Language Function, Baldwin's "Dictionary of Philosophy and 
Psychology." 



3l6 PSYCHOLOGY 

and events which form the basis of our thoughts. For in- 
stance, the copy image which so often arises in our minds 
is analogous to natural signs in this respect; only, of course, 
they are used exclusively in our private thinking to represent 
ideas to ourselves. Like natural signs and ideograms, they, 
too, have given way to symbolic forms, in this case to verbal 
images. 

A similar primitive attempt at concreteness manifests 
itself in the onomatopoetic tendency of language. Such 
words as ding-dong, clang, jingle, mew, fizz, purr, pop, coo, 
etc., are plainly attempts to get as much concrete sensory 
content as possible into the symbols of our thought. These 
imitative words have, however, become purely symbolic, for 
few of us ever image the sensory content which we symbolize 
when using the words. Hence, the word ring serves the pur- 
pose better than ding-dong to symbolize the ringing of a 
bell. In general, we may say that the more a word suggests 
concrete content, the less fitted it is to serve as a symbol of 
meanings. The sensory content aroused tends to draw at- 
tention away from the meaning of the term. 

A study of natural language signs among primitive peo- 
ples, shows that signs tended to lose their imitative con- 
creteness and to become more and more conventional, the 
more they were used. This result we should expect as a 
natural psychological tendency. For, as the power of think- 
ing develops, attention is drawn away from the concrete 
character of the symbols of thought and directed more and 
more to the meanings which they convey. Also, the more 
a natural sign is used, the less need there would be for carry- 
ing it out completely in order to convey the idea. There is 
then a constant tendency to abbreviate them. 

Origin of Language. — Now, among the natural signs were 
some which have been considered the beginnings of our pres- 
ent conventional, spoken language. We refer to the imita- 
tive, vocal signs, such as "bow-wow," "mew," etc. But the 
imitation of the sound which an animal makes to signify the 



CONCEPTION 317 

idea of it, like barking to convey the idea of dog, is in prin- 
ciple a form of imitative gesture. It is different only in that 
it involves the movements of tongue and other vocal organs 
instead of those of hand and arms. 

It seems reasonable to suppose, then, that conventional 
language may be traced back to imitative gesture. Lan- 
guage in the broader sense must have found its origin in 
that stage of mental development where a natural sign of 
any kind was used to signify something beyond itself. As- 
suming the ability to reproduce imitative gestures and imi- 
tative vocal sounds, or the instinctive vocal expressions of 
emotion, all that is needed to make them serve the purpose 
of communication is the mental power of imaging the past 
experiences which have been connected with the gestures .or 
sounds. 

Just as soon as primitive man was able to consciously 
represent to himself the experiences which were associated 
with a certain movement or sound, it was a simple and nat- 
ural thing for him to hit upon the device of reproducing the 
gesture or sound for the express purpose of suggesting the 
experiences to others. The fact that he could exert a certain 
control over others in this way must have given the language 
impulse a strong incentive at the very beginning. 

The advantage which vocal sound has over visible ges- 
tures as a means of communication could not help but give 
it the lead. Vocal signs can be communicated in the dark. 
It is said that certain primitive peoples can communicate 
only imperfectly in the dark with each other, because visible 
gesture is such an important element in their language. 
They, therefore, are obliged at night to go to the fire to talk 
to each other. Vocal signs can also be exchanged between 
individuals who are unable to see each other because of in- 
tervening objects. Moreover, the vocal organs are able to 
function when arms and hands are otherwise occupied, or 
injured, or bound. A still more important factor rests in 
the fact that the vocal organs have no other function to in- 



3l8 PSYCHOLOGY 

terfere with the language function. These are some of the 
causes which have contributed, although perhaps not con- 
sciously, to the selection of vocal signs as the material of 
conventional language. 

There are several current theories concerning the origin 
of vocal language, but they all disregard the connection 
which conventional language has to the primitive language 
of visible gesture. The ''interjedional theory,^' nicknamed 
the "pooh-pooh theory," supposes that vocal language origi- 
nated in the instinctive emotional expressions, such as the 
cry of fear, when used to communicate to others the idea of 
the presence of an enemy, or dangerous object. The ''ono- 
matopoetic theory,''^ or "bow-wow theory," places the origin of 
language in the imitation of some characteristic sound which 
objects make to indicate the idea of the object, as when one 
imitates the barking of a dog in order to convey the idea of 
the dog. The ^^pathognomic theory,'" sometimes spoken of 
as the "ding-dong" theory, supposes that certain objects or 
events forced out, or "rung out,'' of primitive man certain 
vocal sounds which were in some way expressive of, or har- 
monious with and appropriate to the nature of the object or 
event; and that such sounds, being repeatedly "rung out" 
of the organism by these objects or events, finally were used 
to signify them, and so formed the nucleus of vocal language 
signs. Such a word as "zigzag" is an illustration. There 
seems to be a peculiar appropriateness of the vocal expression 
"zigzag" to the course of a zigzag line. The change in 
direction of the line is sympathetically expressed by the 
syllables "zig" and "zag." The English verb suck, German 
saugen, French sucer, also show a kind of harmony between 
the act of sucking and its name. The verb bubble is intrin- 
sically expressive of the action of bubbles. In fact, there 
are in all languages so many cases of the close affinity between 
the names and the objects or events which they stand for, 
that there appears to be some ground for the "ding-dong" 
theory. 



CONCEPTION 319 

But in all these theories of the origin of vocal language, 
there is at bottom the principle of imitative gesture, which 
they neglect. This is evident in the interjectional and ono- 
matopoetic theories. To imitate the cry of fear or the char- 
acteristic sound of an object is really a vocal gesture which 
describes some feature of a situation or object. Even in the 
pathognomic theory, appropriateness between the vocal ex- 
pressions and the things they signify consists, as Stout has 
so clearly pointed out,^ in the imitation by the movements 
of articulation of some feature of an object or event. The 
principle of imitative gesture is not so evident here, but it is 
nevertheless present. In zigzag, for instance, the tongue 
moves in imitation of the course of a zigzag line. To pro- 
nounce "suck/' one must partially imitate the real act of 
sucking. It is even more evident in such a word as "pucker." 
In giving expression to the word "bubble," the lip move- 
ments really imitate the action of bubbling substances. 

The "ding-dong" theory, therefore, proves more than it 
intends to prove. The theory is valuable just because it 
points out the fact that, in the beginning, speech was not only 
sound but movement, and that even here the movement took 
the form of imitative gesture — gestures made by the speech 
organs. This is quite as true of the "bow-wow" theory. 
For instance, barking to imitate a dog consists not only in 
imitating the sound of the dog, but it imitates the move- 
ments of the dog— it describes by imitative gesture the visi- 
ble appearance of a dog barking. By consciously imitating 
the movements of a barking dog with the head and mouth, 
one will discover that the sound "bow-wow" is really caused 
by the gesture. The imitative movements will force a vocal 
expression which is a kind of rudimentary bark, like the dog's 
bark. The sound is really incidental to the gesture. All 
these facts lead us back to the statement made in the begin- 
ning of the discussion that the origin of language may be 
traced back to imitative gesture. 

1 "Manual of Psychology," pp. 484-486. 



320 PSYCHOLOGY 

The origin of language appears to exemplify the growth 
and development of the concept. All attempts to use mean- 
ings in our thinking begin by imaging or reproducing some 
sensory quality of the thing thought of, and making that 
the symbol for the thing. This is essentially the principle of 
imitative gesture. Gradually, however, the tendency to im- 
itate gives way and the symbols of thinking become purely 
arbitrary and conventional. 

Thought and Language. — There is a tendency in some 
quarters to hold to the dictum: "No language, no thought." 
If by language is meant only the verbal forms of conven- 
tional language, then thought may take place without lan- 
guage. We have already seen that we may think in terms of 
concrete images. We may think of the relations between 
things by using the things themselves, or the images of the 
things, as symbols of thought. We may also think in terms 
of natural signs or gestures. It is true, however, that thought 
requires symbols, and words are the most serviceable sym- 
bols. It is also true that the development of language and 
the development of thought take place together, and that 
without the verbal signs of oral and written language our 
systems of thought could never have reached their present 
stage of perfection. There is no reason to suppose, however, 
that in the absence of the invention of words thought would 
have been impossible. 



CHAPTER XIV 
JUDGMENT 

Judgment and Perception. — We have already pointed out 
the fact that every act of perception involves a rudimentary 
form of judgment. Perception contains the recognition of 
whatever is presented to the senses as similar to, or identical 
with, objects we have known before. In this act of recogni- 
tion there is an implicitly experienced relation of identity 
between the sensory presentation and past contents of con- 
sciousness. If our view of perception is correct, we may 
suppose that in the baby's early stages of development each 
perception of its nurse involves a vague and undifferentiated 
experience : ' ' This -thing -that - 1- now -see -is -the - same - thing - 
that-has-bathed-and-clothed-me-before." In perception the 
relation of the present sensory content to past experiences 
is not explicitly experienced. This content is merged so 
completely into the unity of perception that the rudimentary 
j'udgment involved does not come to the surface of conscious- 
ness. In j'udgment, on the other hand, the relation between 
our mental contents of consciousness is explicitly experienced 
and attended to. We may, therefore, define judgment ten- 
tatively as the consciousness of relation between our mental 
contents. In so far as perception involves the relation of 
one mental content to another, it is the beginning of j'udg- 
ment. In taking up the discussion of j'udgment we are, 
therefore, not introducing a totally new process. 

The Nature of Judgment. — Popular thought about j'udg- 
ment is based almost entirely upon the logical treatment of 
j'udgment. The logician is interested primarily in the lan- 
guage expression of thought. He therefore defines j'udgment 
as the expressed relation between two concepts. In formal logic, 

321 



322 PSYCHOLOGY 

a judgment is a proposition containing a subject and a predi- 
cate, with a copula to conjoin them. Two terms verbally 
joined to show a relation between the terms — that is the 
judgment of logic. For the logician the printed or spoken 
sentence, "Iron is a metal" is a judgment, and is thought 
of and treated independently of the real conscious experi- 
ence which is back of it. In psychology, on the other hand, 
we are concerned with the conscious states themselves — the 
actual mental processes that take place when we form judg- 
ments. Psychologically, judgments may or may not be ex- 
pressed in language terms. And, moreover, the language 
form of a judgment may not adequately represent the mental 
process itself. We must therefore observe the actual con- 
scious states in order to get at the nature of judgments. 

Judgment as Apperception. — Psychologists are not all 
agreed in their definitions of judgment. It has been sug- 
gested by Kant that judgment is simply the entrance into 
consciousness of any presented mental content. He assumes 
that no presented content can become clear in consciousness 
until it has been received by, and assimilated to, an organized 
body of knowledge already in the mind. He says:^ "I find 
that a judgment is nothing but the mode of bringing a given 
cognition into the objective unity of apperception." The 
"objective unity of apperception" here means the organized 
body of past experiences in the light of which any given 
presentation is understood or interpreted. For instance, on 
seeing a rose I have an experience which when expressed be- 
comes: "That is a rose." In order to be clearly conscious 
of the rose, the presentation, or sensations which I get from 
the presented object must be referred to that which I have 
previously learned about roses. The combining of this pre- 
viously organized knowledge with the presentation is, accord- 
ing to Kant, the judgment. The judgment is, therefore, in 
this case the conscious reaction to a group of sensory presen- 

^ "Critique of Pure Reason," Supplement 14, Sec. 19, Max Mij.Uer's transla- 
tion. 



JUDGMENT 323 

tations, by virtue of which the presentations, or entering 
cognitions, are properly placed and incorporated into the 
knowledge I already have. This view of judgment is in 
accord with that in the preceding discussion of judgment 
and perception. It was there pointed out that the process 
of apperception is fundamentally a rudimentary judgment. 
If we follow out Kant's view critically, the judgment "That 
rose is red" contains two judgments. The language expres- 
sion of the double psychological process would be: "It (the 
presented thing) is a rose," and "The rose is red." The 
presentation is apperceived (judged, according to Kant) both 
as a rose and as red. This example furnishes an illustration 
of the difference between the language form of judgment 
(logic) and the mental process (psychology) back of it. Th*e 
judgment "That rose is red" is for logic a single judgment 
because the logician neglects the actual conscious processes 
involved in bringing each term of the logical judgment to 
consciousness. Each single term of the logical judgment is 
the result of an implicit judgment which does not show itself 
in language expression. 

Judgment as Belief. — Another view makes judgment the 
conscious act of acceptance which we give to a sensory pres- 
entation or, indeed, to any other mental content. According 
to this view, judgment is a positive attitude of assent or belief. 
Conscious content that does not gain this assent fails, there- 
fore, to develop into judgment. Judgment is something more 
than the entrance of a given content into consciousness. It 
is an attitude which we take toward the content. The atti- 
tude of belief is, accordingly, the true form of psychological 
predication. In this connection we should note that the so- 
called negative judgments, or judgments of disbelief, are neg- 
ative only in the form of the language expression. The 
judging attitude itself is always a positive one. For instance, 
on seeing a counterfeit bill, I may exclaim: "It is not good." 
The judgment here consists in my acceptance of the pre- 
sented content "not good." This acceptance is psychologi- 



324 PSYCHOLOGY 

cally a positive attitude, although the expressed form is 
negative. The judgment involved in the sentence ''The 
table is not round" is my positive acceptance of "not-round- 
ness" as an attribute of the table. Psychologically there are 
no negative judgments any more than there are negative 
perceptions, or images, or memories. It is only from the 
logical point of view that judgments may be called negative, 
and then only because of their external form. 

What distinguishes judgment from mere associations of 
mental contents ? Some recent investigators of the processes 
of judgment contend that the distinctive judging process is 
the acceptance or rejection of conscious content presented 
to the mind as a solution to some problem. The problem 
may be consciously formulated, as when we look at a fabric 
in order to determine its color. Cognitive curiosity, or in- 
terest in the existence or non-existence of things may be 
sufficient to supply the problem. Accordingly, acts of judg- 
ment will arise whenever problems (implicitly or explicitly 
formulated) are set in consciousness, and whenever the con- 
tents supplied by association are received as satisfying or not 
satisfying the requirements of some intention of conscious- 
ness. The intention or problem may involve the question 
of whether a certain state of affairs is or is not true. This 
view of judgment is similar to the view which looks upon 
judgment as belief. They both presuppose that conscious 
content may be poised or held in consciousness without ac- 
ceptance or rejection. Accordingly, consciousness is sup- 
posed to have a twofold character — that of conscious act 
and that of conscious content. Judgment, then, is the act 
of acceptance or rejection of conscious content. 

Judgment as the Ascription of Meaning. — Still another 
view of judgment considers it to be the mental act of ascrib- 
ing meaning to whatever presents itself to consciousness for 
interpretation or comprehension. This view has much in 
common with the view that judgment is a form of apper- 
ception. For it is plain that whatever meaning is ascribed 



JUDGMENT 325 

to a thing depends upon the nature of our past experiences 
— upon the character of the organized systems of knowledge 
which have been previously developed in the mind. In other 
words, we judge (ascribe meaning to) a new situation in the 
light of past experience. When a given stimulus presents 
itself, the mental act of giving it meaning is an act of apper- 
ception. In a large number of cases, the presented object 
(the given) and its meaning are so closely and immediately 
united that the act of relating them is really a perception — 
a direct apprehension. The synthesis of the given and its 
meaning is so immediate that the distinction between them 
is not evident. But in other cases the meaning does not fol- 
low as closely upon the heels of the given. Just what the 
presented object is, or what its functions and attributes are 
— in other words, what its meaning is — is not immediately 
grasped. It is then necessary to search for and find a mean- 
ing which can be ascribed to the given. This mental act is 
much more plainly a judgment. However, the difference in 
the two classes of cases may turn out to be only a difference 
in the immediacy of the synthesis of the given and its mean- 
ing. If, for instance, a familiar object with a seat, four legs 
and a back are presented to my senses, I immediately appre- 
hend (perceive) it as a chair. But if, on the other hand, an 
unfamiliar object, with three legs supporting a tilted board 
upon which is mounted a large wooden wheel, is shown to 
me, I am for the moment unable to place it in my mind. I 
should then be obliged to search for a meaning to give it be- 
fore I could understand the thing. If I were acquainted 
with early colonial customs, I should then recognize it as a 
spinning-wheel. In the one case, the meaning comes without 
delay and is not sundered from the given. In the other case, 
the meaning is delayed and is consciously united with the 
given. In one, the meaning is implicitly, and, in the other, 
explicitly, ascribed. However, according to the view we are 
discussing, both cases are fundamentally the same, and are, 
psychologically, judgments. Even granting the soundness 



326 PSYCHOLOGY 

of this view, it would be more convenient and less confusing 
to apply the term judgment only to those cases where mean- 
ing is explicitly ascribed to whatever is presented to con- 
sciousness, thus allowing the term perception to include all 
cases of direct apprehension. Such a distinction would be 
in accord with the point of view taken in the beginning of 
this chapter. 

Judgment as Comparison. — A view of judgment which is 
older than any so far mentioned is the one that considers 
judgment as involving the process of comparison. We judge 
when we compare. Or, to turn the statement about, in 
order to judge we must compare two presentations, ideas, 
or concepts, and mentally assert some relation between them. 
Thus we form judgments when we compare two weights and 
decide whether they are alike or different in weight. It is, 
of course, true that we may make judgments in this way, 
but judgments are certainly not limited to acts of compari- 
son. Judgments which assert existence, as "There are 
twelve months," and impersonal judgments, as "It rains," 
do not involve comparison. Even where judgment by 
comparison is possible, careful observation has shown that 
it may take place without comparison.^ For instance, in 
the experiment of judging the likeness or unhkeness of 
two weights, it would seem that when the subject lifts the 
second weight he must recall the impression made by the 
first weight and compare it with that of the second weight 
in order to judge whether the second weight is the same 
or different. But investigators have reported that no recol- 
lection of the first weight need be present when the judgment 
is made. The second weight is therefore not consciously 
compared with the first weight. The judgment of "same" 
or "different" is made immediately upon the impression pro- 
duced by the second weight without any conscious recall of 
the first weight. The first weight leaves a conscious "set" 
or adjustment which prepares for the judgment and when the 
' Schumann, "Zeitschrift fiir Psychologie," 1898, XVII, 119. 



JUDGMENT 327 

second weight is lifted the judgment of "same" or "different" 
is made without any conscious reference to the first weight. 
The judgment in such cases depends of course upon the 
nature of past experience (the experience of the first weight) , 
but it is not the result of conscious comparison of the first 
weight with the second weight. The judgment comes as 
immediately and directly as the recognition of a familiar 
object. Every-day experience furnishes many illustrations 
of judgments which might follow the process of conscious 
comparison but which actually take place without it. On 
meeting a man over six feet in height we immediately form 
the judgment — "very tall" — "taller than usual," without 
consciously recalling and representing to ourself the heights 
of other men and comparing the presented individual with 
those we recall. We are already prepared by our past ex- 
perience to form the judgment directly, without conscious 
recall and without comparison. Thus in the illustrations 
we see that the judging process may approach that of imme- 
diate apprehension or perception, which is essentially the 
entrance of the given into a predeveloped system of knowl- 
edge. 

Judgment as Evaluation. — A popular way of considering 
judgment looks upon it as a process of evaluation. When 
a given presentation is evaluated according to some stand- 
ard, the mental process is that of judging. Thus the stock- 
man judges the weight of a fat steer. The standard by 
which he judges is that which he has formed in his former 
experience with cattle. The judge on the bench after hear- 
ing a case renders judgment, i. e., gives a sentence, corre- 
sponding to the offense or fixes the damages in accordance 
with the losses sustained. In both instances a given presenta- 
tion or situation is evaluated by referring it to a standard. 
The standard of judgment may be in certain cases consciously 
represented, and the given presentation compared with it. 
The judgment is then formed as a result of the comparison. 
Or, on the other hand, the standard may not be consciously 



328 PSYCHOLOGY 

represented when the judgment is made. We have here 
the same mental process that we find in judgments of abso- 
lute pitch. Those few musicians who possess the power of 
absolute pitch have formed such close associations between 
the different musical tones and their names that when they 
hear a tone, its name immediately arises in consciousness. 
Likewise the stockman in his extended experience with cattle 
has formed close associations between their visual appearances 
and the scale of weights. When a certain size and form is 
presented, his judgment of weight takes place immediately 
without reference to a clearly defined standard. In such 
cases judgment is merely a sequence of mental states which 
may be likened to the association of ideas. 

Because of perfect famiharity gained through extended ex- 
perience in a certain field of knowledge a given presentation 
may call up immediately its evaluation without the mediation 
of the standard of judgment which was earlier an essential 
element in the process. The expert bank teller judges a bill 
to be good or bad immediately without consciously repre- 
senting to himself his standard of judgment. On the other 
hand, many judgments of evaluation are made only after the 
given presentation is referred to and compared with a men- 
tal standard which is consciously represented at the time of 
judgment. 

There is a tendency in certain quarters to base judgments 
of evaluation on the feeling processes. It has been said 
with some degree of truth that the judgments of value 
which we pass upon the facts and events of life depend 
not so much upon the rational ordering of mental contents, 
as upon the personal choices determined by our feelings. 
Consequently, to approach, or appreciate, reality we must 
"feel" it, or in a way "live" it. The judgments which we 
form concerning the value of works of art (aesthetic judg- 
ments) are used as illustrative of all judgments (evaluation). 
We evaluate a painting or an opera only when it appeals to 
our feelings. There is, therefore, an emotional standard for 



JUDGMENT 329 

such judgments. According to this point of view, the basis 
for our estimation and appreciation of values lies deeper 
than our formulated knowledges. There is no doubt of the 
fact that the feelings do modify the cognitive processes to a 
marked degree, but we cannot admit that the feelings form 
an independent and distinct ground of judgment. Where 
the cognitive standards for evaluation are not plainly evident 
it is very probable that the standards of evaluation are to be 
found among former cognitive experiences which have been 
thoroughly assimilated and submerged into our personality. 

In whatever way we may consider judgment — whether 
(i) as the entrance of a given presentation into consciousness, 
or (2) as beUef, or (3) as the ascription of meaning to the given, 
or (4) as comparison, or (5) as evaluation of the given, the 
essential mental process in judgment is the arousal and reac- 
tion of conscious content already in the mind upon newly 
entering content. The judging process is best typified by the 
view that judgment is the ascription of meaning to the given. 
The entrance into consciousness of any given presentation 
is identical with that of ascription of meaning. The reac- 
tion of consciousness takes place only when the given pres- 
entation enters consciousness and is at the same time inter- 
preted in the light of some mental standard which has grown 
up through past experiences. Belief also may be considered 
as intimately connected with the entrance of the given into 
consciousness if not part and parcel of the same process. Be- 
lief is a mode of conscious reaction, determined by standards 
of past experience. I cannot see how any given presentation 
can enter consciousness without involving some degree of 
belief or disbelief. 

We have already seen that comparison may be and usu- 
ally is an immediate conscious reaction upon the second term 
of the comparison without the formal representation in con- 
sciousness of the first term. The judgments "longer," 
"shorter," "brighter," "smaller," etc., may be direct and 
immediate conscious reactions made at the instant the 



330 PSYCHOLOGY 

second of two objects is presented. This has been demon- 
strated in the experiment of Hfted weights. Evaluation, 
too, results from the direct and immediate reaction of stand- 
ards of experience awakened by entering contents of con- 
sciousness. Sometimes this reaction of consciousness is 
merely that of simple apprehension in which the content 
already in the mind is not formulated and attended to. 
In such cases we have implicit judgments. In judgments 
proper, however, the standards by which we interpret the 
entering content are consciously formulated and attended to. 
In this case there is a dual act of attention. Attention is 
divided between the mental contents. This division of the 
attention brings out the relation between the contents and 
unifies them into a single whole. 

In its most developed form, then, judgment is the proc- 
ess of consciously relating one mental content to another. 
Judgment is therefore the experienced relation between two 
mental contents. The relation may be of any kind what- 
ever: relations of dependence, substance and attribute, cause 
and effect, whole and part, sameness and difference, temporal, 
spatial, etc. The simplest and most primitive judgments 
are one-term judgments such as the inter jectional judgment, 
"Wolf!" the impersonal judgments, "It rains," and the de- 
monstrative judgments, "There is a tree." In these cases 
the mental content by which we interpret the given is not 
consciously formulated, and for this reason it is difficult to 
differentiate the judgments from simple perception. Logi- 
cians have always had trouble with these judgments for the 
reason that in logic judgments are supposed to be made up 
of two terms — a subject and a predicate. What then are 
the terms in such judgments as "It snows," "Fire," "There 
is a tree"? Psychologically there is no difficulty when we 
understand that the second term that the logician is looking 
for is the mental standard by which we interpret, or ascribe 
meaning to the given presentation. 

In our discussion of judgment as the entrance of a given 



JUDGMENT 331 

presentation into consciousness, ascription of meaning, belief, 
comparison, and evaluation, we have so far spoken al- 
most entirely of one-term judgments, or judgments involving 
a single presentation and its interpretation. Now, many of 
the judgments of the logician, having two terms when ex- 
pressed in language form, are psychologically one- term judg- 
ments. The inter jectional, the impersonal, and many of 
the demonstrative, and assertative judgments consist in the 
single act of giving meaning to a given presentation. There 
are, however, many two-term judgments in the psychological 
sense. Thus in the judgment, "The rose is red," there are 
two presented contents which are united in the judgment. 
In such judgments, in addition to the act of joining the two 
terms through some explicit relation, there are, psychologically, 
two interpretations, or judgments, involved which are not 
usually considered in logic. They consist of the entrance 
into consciousness of the two presented contents. On the 
other hand, it is the relational joining of the two presented 
contents which constitutes the judging process of formal 
logic. 

Kinds of Judgments. — There are many ways of grouping 
judgments. Sometimes the character of the mental con- 
tents related in the judgment, and sometimes the character 
of the relationship itself between the contents determines the 
classification. Even the form of the language which expresses 
the judgment is sometimes used as a basis of classification. 

Grammarians and logicians speak of assertative judgments , 
hypothetical judgments, and disjunctive judgments. The as- 
sertative judgment is a simple assertion, as, "The grass is 
green." The hypothetical judgment is an assertion subject 
to a given limitation, as, "If it rains, he will get wet." The 
disjunctive judgment is an indeterminate assertion, naming 
two or more possibilities which may exist in relation to a 
given subject in such a way that the truth of one excludes 
the truth of all the others, as, "He is either a Democrat or 
a Republican." 



332 PSYCHOLOGY 

Judgments may be classed as individual judgments, gen- 
eral judgments , and abstract judgments accordingly as they deal 
with a single thing, a group of things, or an abstract quality. 

Perception judgments are judgments made about things 
presented to the senses. They may take the form of inter- 
jectional judgments, as when the shepherd boy cries out: 
**Wolf!" Or they may be impersonal judgments, as, "It 
rains." In the impersonal judgment the field of perception 
is taken in an indefinite manner as the object of thought. 
On the other hand, when attention is narrowed to one par- 
ticular point in the field of perception the judgment is a 
demonstrative judgment, as, "That is a tree." Genetically 
the interjectional and the impersonal judgments are primi- 
tive forms of judgment. Perception judgments may also 
be looked upon as judgments of naming, or, judgments of 
classification, as, "That is an animal." If we should carry 
out the classification suggested we have not only judgments 
about things perceived, but judgments about things remem- 
bered, things imagined, and things generalized into concepts. 

Among judgments of comparison, or judgments of likeness 
and difference there are mediate judgments and immediate 
judgments. We have pointed out that in comparing two 
lifted weights the experience of lifting the first weight may 
be kept explicitly in mind while the second weight is being 
lifted, and compared with it. In this case the resulting 
judgment is a mediate judgment. On the other hand, when 
the judgment of Ughter or heavier is made directly without 
explicitly recalhng the impression of the first weight, the 
judgment is an immediate judgment. 

Judgments may be classified according to the kinds of 
relationships which subsist between conscious contents. 
This principle if carried out consistently would give a long 
list of judgments. But since the relationships of cause and 
effect, of substance and attribute, and of space and time 
occupy a large part of all thinking, the classification of judg- 
ment upon this basis is limited to judgments of cause and 



JUDGMENT ^T,;^ 

effect, judgments of substance and attribute, and judgments 
of time and space. Whenever we think of one thing or proc- 
ess as existing or taking place as a consequence of another 
thing or process we employ the judgment of cause and effect; 
as, "Poverty brings misery." Whenever we think of a thing 
and its essential quality or characteristic we employ the 
judgment of substance and attribute; as, "The ring is round." 
Judgments of time and space are expressed by such words as 
earlier, later, before, after; and right, left, above, below, etc. 
Analysis and Synthesis. — ^Judgment may be considered 
both as analysis and synthesis. We employ judgments in 
dissecting relatively total experiences into the different con- 
stituents of which they are composed. Thus in the judg- 
ments, "The grass is green" and "Circles are round, "we 
are analyzing out of the percept in one case, and out of the 
concept in the other, elements which are already present in 
our consciousness of them. They are therefore analytic judg- 
ments. On the other hand, we employ judgments in putting 
together contents of consciousness which have never been 
together before or which are not obviously conjoined in 
our consciousness until the judgment takes place, i. e., we 
add something to a given conscious state. Thus in the 
judgments, "Grass is valuable" and "Circles are symbols 
of eternity," we are adding something to our concepts of 
grass and circles which was not previously present, and, 
evidently not contained in them. They are therefore syn- 
thetic judgments. If, however, the ideas of "value" and 
"eternity" were already parts of the concepts at the moment 
the judgments were made, the judgments must be considered 
as analytic. Whether a judgment is analytic or synthetic 
depends upon what is in consciousness previous to the judg- 
ment. If in the judgment, "Lead is heavy," we suppose 
that the concept of lead already included the idea of heavi- 
ness as a constituent part of it, then the judgment is analytic. 
On the other hand, if we suppose that our consciousness of 
lead did not at the time include the idea of heaviness but that 



334 PSYCHOLOGY 

the two contents were separate elements of thought, and 
were united by the judgment, then the judgment is synthetic. 
Without doubt we do put together separate mental contents 
in a synthetic way and note relationships of which we were 
not previously aware. On the other hand, relationships of 
which we are only vaguely cognizant in a single total experi- 
ence, perceptual or ideational, may be brought to the focus 
of consciousness and made clear in the analytic judgment. 

In judgments of perception where the two contents of 
the judgment are expHcitly presented to the senses the proc- 
ess is obviously analytic, as, "The paper is white." But 
if one of the contents is supphed out of past experience, i. e., 
remembered, the judgment is synthetic, as, ''The paper be- 
longs to John." In this case we are adding to the percep- 
tion a content not expHcitly present in it. 

Sometimes what we add to a given percept or concept 
may come not from specifically remembered past experi- 
ence, but from generalized knowledge, or general truth. 
It is just here that synthetic judgment passes into inference. 
If, for instance, I conclude that a certain piece of lead which 
I see is heavy, not because I remember that it is heavy, but 
because I know that "All lead is heavy," then the judg- 
ment is an inference — the result of a reasoning process de- 
pending upon the presence in the mind of a general truth. 

Judgment, therefore, may be traced from apperception to 
reason through gradual changes in the explicitness of the 
relationship involved. In the perception or apprehension of 
any external object past experiences are implicitly added, 
or related to the given presentation. The object is apper- 
ceived, or received into the organized body of knowledge. 
This process is a primitive form of judgment — an implicit 
judgment. In the synthetic judgment the added content 
is explicitly and consciously joined to the present content 
of consciousness through memory. In inference the added 
content comes through generalized knowledge.^ 

1 For a fuller statement see Pillsbury : "The Psychology of Reasoning," pp. 

172-175- 



JUDGMENT 335 

From the genetic point of view judgment is an analytic- 
synthetic process. It is by means of judgments that we 
first break up our vague total experiences into definite and 
distinguishable parts and organize them into systems of 
related knowledges. The baby's world is at first a vague, 
confused mass of experience. Judgment begins in the analysis 
of this total experience into its constituent elements, but 
at the same time these elements of knowledge are synthe- 
sized through judgments into organized systems of knowledge. 

Judgment and Concept. — ^If we examine the beginning of 
concepts we shall find that they originate in rudimentary 
judgments, or vague recognitions of relations between the 
parts of experience. As the child analyzes his hazy experi- 
ences into their elements, and sees the relations between them 
more clearly, his ideas about things become more definite. 
Things assume meaning for him. The mental activity by 
which he clears up and marks off his world of things into 
definite groups of meaning is essentially the process of judg- 
ment. Thus "mother" comes to mean "to feed," "to 
rock," "to bathe," in short, all forms of maternal care; 
"ball" means "to roll." These meanings, however, are 
based upon particular recognition of relation between dif- 
ferent contents of his experiences. The later development 
of his concepts is brought about through expKcitly formed 
judgments. Each new characteristic which we discover 
about an object gives a new meaning which is straightway 
embodied in the concept. The concept grows, therefore, 
both by the addition of new relationships given through 
judgments and by the clearing up of all relationships which 
are already vaguely present in our experience. Judgment is, 
therefore, the conscious process by which we arrange our 
experiences into systems of knowledge (concepts). The 
concept then becomes a series of potential judgments, any 
one of which is available for use whenever needed and called 
for by the context of consciousness or purposes of thought. 

Not only, then, is judgment the means of forming con- 



336 PSYCHOLOGY 

cepts, it is also the means of making use of concepts in think- 
ing. From the psychological point of view all the judgments 
making up a concept cannot be thought of as actually existent 
at any one moment. It is, therefore, only for convenience 
sake that we sometimes speak of a concept as a sum of judg- 
ments. What is really meant is better expressed by speaking 
of the concept as a centre of meaning from which radiate a 
series of possible judgments, only one of which can become 
explicit and definite at any one instant of conscious activity. 
Judgment is the means by which we analyze and unfold the 
developed concept and transform its meaning into definite 
forms for use in thinking. 

Judgment as the Fundamental Cognitive Activity. — Con- 
sciousness of relation is a fundamental cognitive experience. 
Without it, consciousness would reduce to a series of separate 
mental flashes, and would be without any kind of continuity. 
To be sure, some schools of thought have denied that the con- 
sciousness of relation exists. Hume, for instance, said: "The 
stream of thought is not a continuous current, but a series of 
distinct ideas, more or less rapid in their succession." The 
old intellectualists also denied that consciousness of relation 
can be a content of consciousness. They held that no such 
experience can be found as a content in consciousness. In- 
stead of consciousness of relationship, they substituted an 
"act of pure thought," above and entirely different from 
conscious content, which unites the separate sensations and 
ideas, and gives continuity to consciousness. James, on 
the other hand, is an able defender of consciousness of rela- 
tion as a content of consciousness. He likened the stream 
of consciousness to the movements of a bird in the tree tops — 
an alternation of flights and perchings. The resting-places 
correspond to the substantive contents of consciousness, 
(sensory experiences and ideas) and the flights to the tran- 
sitive contents (consciousness of relation). We have, he 
said, a consciousness of "and" and "if" and "by" and 
"but" quite as truly as a consciousness of "blue" or "cold." 



JUDGMENT 337 

There is in my mind no doubt of the fact that sensory 
impressions and ideas appear in consciousness in a relational 
aspect, and that the consciousness of relation is a necessary 
and fundamental constituent of conscious activity. From 
the very first sensory impressions appear as similar or differ- 
ent from preceding impressions. The consciousness of differ- 
ence may be vague and indefinite, but if it were not present 
there would be no differentiation of sensory experiences. 
Rudimentary and nascent experiences of recognition depend 
upon the relational experiences of sameness, or similarity. 
We have seen that perception of a simple object involves 
some degree of recognition of the sensory experiences as the 
same as, or similar to previous experiences. We could not 
apprehend the simplest object without this consciousness of 
relationship. The experienced connection of sensory stimu- 
lation with something already familiar is a primitive and 
implicit form of judgment. Perception and judgment are 
therefore different stages in the same fundamental conscious 
activity. We have also seen that the concepts are both 
formed and made use of in thinking through the instrumen- 
tality of judgments, and we shall see later that reason is noth- 
ing more than the manipulation of judgments in a relational 
way. From the simplest direct apprehensions to the most 
complex cognitive activities some form of judgment is always 
present and fundamental. 



CHAPTER XV 
REASONING 

Inference. — It was stated in one of the previous chapters 
that the three aspects of reasoning are conception, judg- 
ment, and inference. These are not separate processes, but 
interdependent mental activities which we have separated 
only for the purpose of discussion. Judgment, as we have 
seen, is involved in the concept, and we shall soon see that 
inference and judgment are but different stages of the same 
process. Indeed it is difficult at times to distinguish between 
judgment and inference. Moreover, just as the line between 
judgment and perception is psychologically not a hard and 
fast one, it is also not an easy matter to determine just how 
much of inference is contained in perception. Helmholtz, 
for instance, looked upon perception as unconscious infer- 
ence. 

Inference is the process of consciously adding to a given 
presentation or direct cognition something not obviously 
contained in it. If I say that the paper before me is white, 
it is evident that the whiteness is present in the presentation, 
and that I am not transcending what is given in direct cogni- 
tion in making the judgment. But if I say that the paper 
will burn, I am supplying something not contained in the 
present presentation. This something is supplied out of 
my past experience and I am therefore transcending my 
direct and immediate consciousness of the object. I may 
infer that the crystal in my watch will break if it drops upon 
the floor; that the lead paper-weight upon the table is heavy; 
that all men are mortal, etc., etc. In each of these cases I 
am making a judgment, and at the same time there is present 
in my mind, more or less explicitly, a reason or ground, for 

338 



REASONING 339 

the thought entertained. We may say very crudely that 
inference is judging with a reason, or conscious ground, for 
each judgment. In inference, the conscious content added 
to the given presentation is accepted because of some felt 
reason, or ground for it. For instance, I add to the presenta- 
tion of that paper-weight the thought of heaviness, because I 
am at the moment conscious that all lead is heavy. If I 
had in mind no reason, no conscious support for thinking the 
paper-weight heavy, the experience could not be called 
an inference proper, but simply a judgment. 

Inference and Perception. — We said that inference is the 
process of adding to a given presentation or direct cogni- 
tion something not obviously contained in it. Now, ev- 
ery act of perception goes beyond the sensory presentation 
and adds content not present to the senses. For instance, 
when I perceive the paper-weight on the table, my experi- 
ence of the object depends upon more than that given in 
direct cognition. How, for instance, can I say the object 
is lead without drawing upon the knowledge already in my 
mind and supplementing the given sensory experience by 
something not obviously present? Here we have the "un- 
conscious inference" of Helmholtz, When we examine our 
perceptions carefully, we are struck with the poverty of 
the given sensory experiences and with the wealth of conscious 
content read into them through the process of apperception. 
Very Httle is given by external stimuli, much comes out of 
the contents of past experience. If the word "^vxv were 
shown or spoken to a person ignorant of the Greek language 
he would experience the sensory visual form of the word, 
or hear the sound, but form or sound would mean nothing 
to him. But if he were familiar with the Greek language 
he would understand the word directly. It would then 
have meaning for him. In the case of the lead paper-weight 
just referred to, the sensory presentation (color, etc.) means 
"lead" for me, and I perceive it as lead. In a similar way 
all the familiar objects about me — books, tables, chairs, etc.-- 



340 PSYCHOLOGY 

have meanings by virtue of which I apprehend them directly. 
But suppose an object with which I am not familiar — several 
small shell-hke beads strung together — comes to my notice. 
I am at first unable to apprehend it. I stop and search for 
its meaning and then it dawns upon me that it is a piece of 
Indian money, or wampum. In this case my understanding 
of the object is indirect, mediated by my knowledge of early 
Colonial times. The mental process by which I find its mean- 
ing is very much like inference, or reflective thought. There 
are, then, two ways of grasping the meaning of a given pres- 
entation — direct and indirect understanding. In direct 
understanding the object and its meaning are so closely 
united that they appear as one. In indirect understanding 
the object and its meaning are sundered until they are brought 
together by thought. In one case we apprehend (perception) 
and in the other we comprehend (inference) a given presenta- 
tion. The difference between perception and inference lies 
only in the manner in which the given presentation is supple- 
mented or interpreted. If the interpretation is immediate, 
we have perception, but if the interpretation is delayed and 
involves reflection we have inference. 

Inference and Judgment. — Inference always ends in Judg- 
ment, but all judgments are not inferences. How shall we 
determine when a judgment rests upon inference and when it 
does not? If a given object is understood at a glance, as in 
the judgment, "This is paper," we have a simple perception, 
judgment, or mere apprehension. If we say, "This paper is 
white," we have an analytic judgment. In this latter case 
both subject and predicate are given and analyzed out of 
a total sensory presentation. But if we say, "This paper will 
burn," it is not easy to determine whether we are dealing 
with a sjTithetic judgment, or with inference. If the quality 
of combustibility is supplied by a specific memory act, or 
if through familiarity with paper and its attributes the thought 
of combustibility follows the consciousness of the paper 
immediately or habitually as an association, the mental 



REASONING 34 1 

process is a synthetic judgment. But if the quality of com- 
bustibility is added because of the larger thought, "All 
paper will burn," then the judgment rests upon an infer- 
ence. Since the conscious ground for inference may be 
present in all degrees of exphcitness — from the case where 
it is only implicitly present to those cases where it is con- 
sciously formulated and expressed — it is evident that syn- 
thetic judgment shades ofif gradually into inference. 

Inference and Concept. — In the judgment, "That paper 
will burn," the inference consists in regarding the presented 
object, " that paper," in the Hght of a larger body of knowledge 
about it. Now, since the concept "paper" is a group, or 
system of meanings which points out or signifies this larger 
body of knowledge, it becomes evident that inference is the 
act of making expHcit the meanings stored away in the con- 
cept. Inference, then, may be looked upon as the process of 
analyzing the concept, selecting the proper meanings and 
making them explicit in judgment — an unfolding of the con- 
cept in the interest of some problem present in the mind. 
For instance, in this particular case I might be searching for 
material to kindle a camp-fire. When, therefore, a part of 
this particular system of knowledge is presented to conscious- 
ness, the part not presented but needed in the solution of 
the problem is called into action. Inference, then, makes 
actual and explicit what is potential and implicit in the 
concept. If it were not for the fact that knowledge organizes 
itself into systems in which one part sustains relations to other 
parts, and in which the system as a whole subsumes all its 
parts, inference would be impossible. Psychologically, of 
course, the whole system is never presented at any one mo- 
ment, but its parts are potential in the concept in the form of 
meanings. Inference may be regarded as a penetrating insight 
into or a searching analysis of our concepts for the purpose 
of revealing the solution of a problem before the mind. 

While inference involves analysis, it also involves syn- 
thesis. It is quite as truly the act of adding new meanings 



342 PSYCHOLOGY 

to our concepts. For instance, my individual notion "that 
paper" may not contain the meaning "combustibihty." 
It may not occur to me that that piece of paper will burn 
until I have analyzed this characteristic out of my general 
knowledge and added it by means of the inference to my 
individual concept "that paper." Inference is therefore 
synthetic as well as analytic. We shall have more to say 
about this point when we consider the deductive and induc- 
tive methods of thought. 

The Nature of Reflective Thought, or Reasoning. — A mere 
succession of mental states does not constitute thinking in the 
highest sense. Thinking is not merely a series of conscious 
states, but a sequence of conscious states in which each 
state determines the next as its consequence. We recognize 
this when we speak of the "thread of thought." Thinking 
is properly limited to the acceptance of ideas because they 
rest upon evidence or knowledge which transcends imme- 
diate presentation. 

Reflective thought involves the awareness of the grounds 
for our conclusions at the time they are made. Much of 
our so-called thinking, however, does not involve the grounds 
for belief. Oftentimes we take things for granted, either 
because we accept the word of others, or because of tradition, 
or because we are influenced by our own personal advantage 
or emotional interests. In such cases there is no examination 
of the real grounds for our conclusions. Superstitions and 
prejudices arise in this way. Belief in protective tariff, or 
free trade, in the fatal outcome of thirteen at table, in our own 
possessions as the best in the neighborhood, and in our own 
actions as right, etc., etc., too often arises not because we 
consider these beliefs in the light of the evidence that supports 
them, but because of the factors just mentioned. Locke 
says that the lack of reflective thought can be traced to such 
sources as (i) the tendency to depend upon the thought of 
others and thereby avoiding the pains and troubles of think- 
ing for ourselves, (2) the tendency to put passion in the 



REASONING . 343 

place of reason, and (3) the lack of knowledge of facts due to 
circumscribed or limited experience. Now, while psychology 
is not concerned with the question whether a given thinking 
process is correct or incorrect, it is interested in determining 
what mental elements are found in both good and bad think- 
ing. It may, therefore, point out the difference between the 
thinking process which utihzes the grounds or warrant for 
its conclusion and the thinking process which does not. It 
is this difference which distinguishes reflective thinking 
from mere association, or succession of ideas. The man who 
reads the barometer and predicts rain may, or may not, be 
thinking in a reflective way. If he understands the relation 
between a low barometric reading and low atmospheric pres- 
sure, and if he understands why low atmospheric pressure 
is favorable to storm formation, then his conclusion may 
rest upon and come out of this understanding. In this 
case, he is exercising reflective thought, or reason. But if 
the relation between low barometer and storm formation is 
no part of his thought — if he thinks or predicts rain simply 
because he merely associates low barometer with rain, then 
his thinking is of the unreflective type. 

The Steps in Thinking. — Dewey, in his excellent little 
book, "How We Think," ^ analyzes a complete act of thought 
into five distinct steps: (i) the problem, or felt difficulty; 
(2) the location and definition of the problem; (3) suggestions 
of possible solutions; (4) the development of the implications 
of the suggestions; (5) further observation and experiment 
leading to acceptance or rejection of the suggestions. This is 
a formal and logical outline of the phases of a more or less 
protracted series of thoughts centering about some problem. 
We may, however, profitably examine it for the light it throws 
upon the psychology of thinking. The first step refers to 
the fact that reflective thought originates in the presentation 
to consciousness of some perplexity or difficulty. If every- 
thing presented to us could be understood at a glance there 

^ Chapter 6. 



344 PSYCHOLOGY 

would be no occasion for thought. The second step con- 
sists in comprehending the nature of the difficulty or problem. 
In most cases the presentation of the problem and its loca- 
tion and definition come to consciousness at the same time. 
Steps one and two are often not separable. The third step 
consists in the arousal of suggestions for the solution of the 
problem. This step is inference as we have discussed it. 
The suggestion is something not presented in the given situa- 
tion, but supplied out of our general knowledge. The fourth 
step is finding out what implications follow the suggestion, 
and the fifth step is determining through observation or experi- 
ment whether the implications tally with the facts as found in 
further observation of the given situation. This last step is 
the verification of the suggested solution. Until this takes 
place the conclusion is hypothetical. If the implications 
are found to be true then we accept the suggested solution 
as the true one. We may use Professor Dewey's illustration of 
the steps of thinking in a particular case.^ Suppose that a 
man on entering his rooms finds the contents of his drawers 
emptied upon the floor and everything in confusion. At 
first he is perplexed. Here is something to be explained. 
Steps (i) and (2) — the problem and its definition — appear 
together, because he understands the nature of the problem 
at once. The next step (3) is the arousal of suggestions. 
Burglary occurs to him as an explanation. Other suggestions 
might also come to mind — ^pranks of children — some friend 
may have been playing a joke. If burglars have been in 
his rooms then he will find his jewels and money gone and the 
locks forced. This is step (4) or the development of the im- 
plications of the suggestion. Step (5) is further observation 
to find out if the implications are true. Carrying out this 
step, he finds that one of the windows has been broken open 
and that all his money is gone. This closes the matter and 
he accepts the h3^othesis as a reasonable one. 

Now, it is plain that the central psychological process 
» See Dewey, "How We Think," chap. 7. 



REASONING 345 

among these various steps is the inference. It is found both 
in the arousal of suggested solutions of the problem, and in 
the development of the implications of the suggestion. When 
the man in the illustration passes in thought from the presented 
situation (disordered room) to something not presented 
(burglars) he is making use of inference. Likewise his mental 
process is inferential when he concludes that if burglars have 
entered his rooms he will find his money gone and the doors 
or windows forced. In the one case the movement of thought 
is from presented particular things to some general principle 
of explanation, while in the other, the movement is from the 
general principle back to particulars. The first movement 
of thought is inductive and the second is deductive. 

Kinds of Reasoning. — Inference, then, may be of two 
kinds: induction, or deduction. It is deductive when we 
pass from a general principle, to some particular case and 
believe in the particular because of the general principle. 
If we infer that a particular piece of lead is heavy because of 
the general law that all lead is heavy the inference is deduc- 
tive. On the other hand, inference is inductive when we 
pass from particulars to a general principle, or law, and believe 
in the general law because of the particulars. If, after observ- 
ing that every particular piece of lead that we have come in 
contact with is heavy, we infer that all lead is heavy, the in- 
ference is inductive. 

It is commonly said (i) that in deduction thought 
goes from the general, or universal, to the particular, while 
in induction thought goes from the particular to the general; 
and (2) that induction precedes deduction. While these 
statements may be true from the point of view of logic we 
shall, in our psychological treatment, have reason to modify 
them somewhat. In actual thinking there is no such thing 
as purely inductive or deductive thought. Any specific case 
of thinking involves both the inductive and deductive proc- 
esses. In some cases the emphasis of thought is on the 
deductive side while in other cases it is on the inductive. It 



346 PSYCHOLOGY 

is evident that deduction is tlie application of old knowledge 
or habits of thinking to new situations, while induction is the 
formation of principles, or habits of thinking. But induction 
cannot take place without the deductive use of old knowledge. 
In so far as it is necessary to identify each particular case in 
the induction which yields the general principle "All lead is 
heavy," the process is deductive. Without the application 
of old knowledge we could not know that the different pres- 
entations or individual cases belong to the class under observa- 
tion. In order to be sure that the induction will be valid 
each new instance must be tested by old principles of knowl- 
edge. The inductive movement, therefore, is constantly 
under the guidance of the deductive process. Moreover, in 
practical thinking induction seeks the general principle 
through particular facts not merely for the purpose of finding 
the general principle but for the purpose of explaining or 
interpreting other particular facts. Induction, then, is not 
so much a movement of thought from the particular to the 
general as it is a movement from particular facts to particular 
facts through the general principle which is used not as an 
end in itself but as a basis or ground of explanation. Neither 
is it absolutely true that induction precedes deduction. They 
both take place at the same time. We do not first collect 
a lot of facts and then generalize them. But from the very 
first the facts are collected under deductive control, i. e., 
each new fact becomes a basis of interpreting succeeding facts. 
Deduction just as truly involves the inductive movement 
of thought. When we apply a general principle to an indi- 
vidual case and infer that a specific consequence will follow 
because of the general principle, the inferred fact then be- 
comes a new instance for the support of the general principle. 
In so far as we think of it as new evidence for the validity 
of the general principle, we are generalizing in an inductive 
way. In practical thinking general principles are rarely so 
complete that they are not fortified or modified by the new 
specific instances or individuals brought under them. When 



REASONING 347 

an individual case modifies or changes a law the thought 
movement is inductive. Concerning the time-worn state- 
ment that in deduction the movement of thought is from the 
general to the particular, observation of real cases of think- 
ing outside of logic books will show that here, too, the move- 
ment is from particular fact to particular fact. Practical 
thinking never starts with a general principle, but rather with 
individual and specific facts. In deduction it is always some 
particular individual presentation that calls for interpreta- 
tion. If we infer that "that paper will burn," or that Soc- 
rates is mortal, the thinking is started by the particular 
piece of paper or the particular Socrates, and proceeds to the 
particular idea combustibility or mortality. In deduction 
it is the individual that is problematic and is given a par- 
ticular interpretation by virtue of the general principle. '^ In 
induction some particular instance makes the general principle 
problematic and either modifies it or supports it. In all cases 
practical thought begins and ends in particular facts. 

There is another form of inference which is usually con- 
sidered inductive in method although it is based upon a sin- 
gle case. I refer to reasoning by analogy. Inference here is 
based upon the similarity between individual cases. If, for 
instance, I infer that salt is sweet because of its similarity to 
sugar I am reasoning by analogy. The argument for mental 
telepathy based upon wireless telegraphy is a case of reason- 
ing by analogy. There is a psychological tendency to think 
that if "a" manifests the characteristic "c," then "b" 
which resembles "a," will also have the characteristic "c." 
The degree of belief aroused will vary with the closeness of 
the similarity between the cases. Logic does not consider 
inference by analogy valid, and we must admit that it is the 
source of many errors in thinking. It is, however, very widely 
used in our every-day thinking. 

Logicians have claimed that deductive reasoning can 
not make any advance in thinking or give any new truth, for 
the reason that the conclusion is already contained in the 



348 PSYCHOLOGY 

general principle. If, for instance, we know that "all lead is 
heavy," we certainly must know that any particular instance 
of lead is heavy, so that the deductive conclusion in such 
cases is not a new truth. We hold, however, that in many 
cases what is contained in a general principle may not 
have been applied by us to all specific cases which can be 
subsumed under it. When we make this application the 
deductive conclusion is a real gain and is, so far as we are 
concerned, a new truth. 

On the other hand, inductive inference has been criticised 
on the ground that it cannot properly go beyond the par- 
ticular facts which have actually been examined and there- 
fore does not add anything to our knowledge. For this 
reason the validity of inductive generalizations has been 
questioned. By what warrant or right can we assert the 
general law that "all lead is heavy"? We are unable to 
examine all the cases, so that the method of enumeration can 
never be completed. Therefore, to pass from the cases 
examined to the general law is the so-called "inductive leap." 
The difficulty here comes from the attempt to consider induc- 
tion as a method of thought separate and apart from deduc- 
tion. The warrant for the so-called inductive leap is essen- 
tially a deductive one. Isolated facts are of no value, they 
cannot be used without some reference back to accumulated 
experience. No particular experience becomes effective ex- 
cept as it is incorporated into old habits or types of thinking. 
The power of induction to establish belief does not come from 
the particulars as particulars, but because they express pre- 
viously established principles or represent typical conditions 
of the world as we know it. To be more exphcit, if we find 
a certain characteristic like heaviness always present in a 
number of cases of lead, we are predisposed by past experi- 
ence to expect that this characteristic will be found in all 
pieces of lead. We have grown to believe in the general 
principle that nature is uniform and law-abiding in her mani- 
festations. We have faith in the general law that whatever 



REASONING 349 

happens under given conditions will always happen under 
the same conditions. So strongly is this principle intrenched 
in our minds that we are wilUng to make inductive generaliza- 
tions upon the examination of a single case provided the 
case is a typical individual of its class. When this is true, 
one case is as good as a hundred. The warrant, then, for in- 
ductive inference is found in a general principle formulated in 
the mind by past experiences. 

Reasoning and the Syllogism. — The logician looks upon 
inference as the process of uniting two judgments in such 
a way that a third judgment, containing a new truth, arises 
as a conclusion. This series of judgments is the syllogism: 

All lead is heavy; 

This paper-weight is lead, 

Therefore, this paper-weight is heavy. 

These three judgments are called the major premise, the minor 
premise, and the conclusion. The major premise asserts a 
general principle. The minor premise applies the general 
principle to a particular case and the conclusion states thfe 
new truth. This is the syllogism of deductive logic. In- 
ductive logic has no one special form of inference, although 
it has several different methods through which inductive 
inference works. To one who has observed what really 
happens when he is reasoning, it is evident that the syllogism 
does not represent the manner in which conclusions are 
reached. In most cases of actual thinking the -only thing 
that is clearly formulated in consciousness is the conclusion. 
The minor premise is rarely if ever formulated when we are 
making inferences. The major premise may sometimes 
come formally to consciousness when there is some doubt 
about the conclusion, but usually the first and only thing to 
appear clearly in consciousness is the conclusion. We do 
not, therefore, proceed in the syllogistic manner in actual 
thinking. Both the syllogism of deductive logic and the 
methods of inductive logic are forms of proof for testing 



350 PSYCHOLOGY 

the truth or falsity of conclusions after they have been made. 
We must, therefore, distinguish between inference as the 
actual mental process which gives conclusions, and proof 
which is the method of logic for testing the results of reason- 
ing. Logic deals with proof, not with the inner mental 
process of making inferences. Logic is, therefore, interested 
in arranging facts into ideal systems (logical concepts and 
judgments), in showing the necessary relationships which 
exist between these systems, and in giving methods of com- 
bining them (syllogism) for the purpose of testing the validity 
of our conclusions. 

If we examine the reasoning process for the purpose of 
finding out how conclusions actually arise, we shall see, as 
we have already pointed out, that they arise through sug- 
gestions, both in the deductive and inductive processes. The 
rise of suggestions is controlled by the laws of association. 
Thus, if I am seeking material to kindle a fire, the moment my 
eyes fall upon paper the next thought is: "That's it, that 
paper v/ill burn." The context of thought (purpose or plan) 
and the link of identity between the idea fire and the idea 
paper, determine the inference. The guidance of the reason- 
ing process is found in the character of consciousness. What 
suggestions arise in a given situation depends upon the past 
experiences, range of information, sagacity, temperament, 
interests, purposes, and recent experiences of the individual, 
together with the context in which the problem for thought 
arises. The ability to pick out of a total situation the vital 
and important characteristics differentiates the mind of a 
Newton or a Darwin from that of the ordinary man. The 
law of association by similarity is most important in reason- 
ing. The mind which easily detects identity among diver- 
sity, or sees delicate and subtle relationships of similarity, 
manifests very clearly the real mental process involved in 
inference. In order to detect identities among differences 
one must possess what James calls "sagacity or the percep- 
tion of the essence of things," i. e., the power to resolve total 



REASONING 35I 

situations into their essential elements and "perceive" 
accurately what they contain — the power to discriminate and 
properly evaluate the elements of whatever is presented. 

Imageless Thought. — It has been very generally assumed 
that the content, or actual mind stuff of our thinking proc- 
esses, is derived from sensory experiences — that the original 
material of thinking comes from the various senses. The 
contents of a thought-process would then be either a sensa- 
tion, or a group of sensations (perception), or images or mem- 
ories of these sensations and perceptions. Even the rela- 
tional elements between the terms of thought are considered 
by some psychologists to have a sensory content. Titchener 
believes that the content of relational consciousness is given 
by motor tendencies, or attitudes, whose representations in 
consciousness are faint kinaesthetic sensations or images. 
Miss Washburn, writing on this same point, says that the 
relational elements of consciousness are the remnants of re- 
mote ancestral motor attitudes. The relational experience 
represented by the word "but," for instance, is now the ves- 
tige of the kinaesthetic sensations originally set up in primi- 
tive organisms by simultaneous stimuh calHng for two incom- 
patible reactions at the same time. The experience, she says, 
was that of a certain suspended, baffled motor attitude. 
In short, the theory of sensationalism holds that all con- 
sciousness, even the elements of reflective thinking, can be 
traced back to sensations. Even those who do not go the 
whole length of sensationalism, i. e., those who are not willing 
to admit that relational elements and meaning are reducible 
to sensations, have all along assumed that every thinking 
process does contain sensory and imaginal content, and 
that thought cannot take place without some substantive 
content of a sensory character either directly experienced or 
imaged. The "no thought without images" theory has been 
recently and vigorously attacked by a group of American and 
German psychologists who believe that they have discovered 
"imageless thought." They contend that thinking may go 



352 PSYCHOLOGY 

on without any imaginal, or sensory, content whatever. Ac- 
cording to them thinking may be carried on, and frequently 
is in its highest forms, in terms of a "pure thought element." 
This non-imaginal thought element can be detected by in- 
trospection, if we accept the statements of the imageless- 
thought psychologists. They claim that, when we think, 
there are elements of thought present in the field of conscious- 
ness which are neither sensory nor affective in character, but 
which nevertheless constitute a content of consciousness. 
They claim further that this content may exist independently 
of sensations or images. Thus Woodworth says:^ "Accord- 
ing to my experience, the more effective the thinking process 
is at any moment, the more likely is imageless thought to be 
detected, provided only one introspects, which is not apt to 
be the case at such moments." 

As an illustration of imageless thought we may quote the 
following from Woodworth's notes i^ "While reading I heard 
some one playing on the piano a piece which I felt at once to 
be familiar, but which I did not at first identify. My first 
attempt at identification was felt to be wrong, and imme- 
diately afterward I identified it properly and with confidence. 
In doing so I thought of the first part of the piece (it was 
Chopin's 'Funeral March,' and the part being played when 
it caught my attention was the trio). Resting satisfied with 
my identification, I was about to turn to other things, when 
it occurred to me to ask whether, in identifying the piece, I 
had had its name present in the form of verbal imagery, and 
I found that I certainly had not; in fact, it required a moment's 
further thought to recall the sound of the composer's name 
and the name of the piece. Nor, in locating the trio as a trio 
and thinking of the character of the march proper, did I 
have an auditory image of the march. I regard the example 
as a good one, since the thought was perfectly overt, conscious, 

* Journal of Philosophy, Psychology, and Scientific Method, III, 1906, p. 703. 
' Ibid., p. 705. 



REASONING 353 

and definite, though it not only began but was completed 
without any image." 

It is claimed that the pure-thought element shows itself 
plainly in cases where we are given a definite mental task to 
do, such as that required in a laboratory experiment. At 
each command to make a definite reaction we know exactly 
what we are to do and yet there is no imagery of any kind 
whatsoever. The thought of the act, or the response, or 
whatever the task may be, is perfectly definite, and yet it 
is imageless. It is also claimed that meaning may be present 
in the mind alone without any image or sensory experience. 
We have described a concept as an image of some kind, plus 
meaning. Now, the advocates of imageless thought contend 
that the meaning may exist in consciousness without the image. 
One may, they say, think of a thing purely in terms of its 
meaning without any visual, auditory, or other image of the 
thing. 

The imageless "thought content, or element" has received 
various names in the different attempts to describe it. Some 
of the descriptive terms are: '^ conscious attitude," "determin- 
ing tendency," "conscious predisposition toward," "problem" 
or ^'Aufgabe," "mental set." 

The imageless-thought advocates have not succeeded in 
winning all psychologists to their point of view. Angell^ and 
Titchener^ have published very vigorous attacks upon the 
theory. It is generally contended that the "conscious atti- 
tudes" or "determining tendencies," constituting, according 
to the imageless-thought psychologists, the whole of thought 
at times, are merely conscious processes of perception or 
thinking which have become so habitual and automatic that 
the imagery involved has dropped into the background of 
consciousness and is, therefore, difficult to detect. In other 

^Psychological Review, vol. i8, 191 1, p. 295. 

' "Experimental Psychology of the Thought Processes," 1909. See also an 
article by Book, "On the Genesis and Development of Conscious Attitudes," 
Psychological Review, vol. 17, 1910, p. 381. 



354 PSYCHOLOGY 

words, cases of so-called imageless thought are cases where 
consciousness is shading off into the automatic and subcon- 
scious tendencies and reflex responses, where there is not only 
no imaginal content, but no conscious content distinct enough 
for introspection. 

Roughly speaking, there are at the present time three 
groups of psychologists distinguished by their attitudes to- 
ward imageless thought. First, there are the sensationahsts 
who believe that all thought processes are carried on in terms 
of sensations, or images, or both. They believe that meaning 
and relational consciousness are represented by sensory con- 
tent of some kind. Second, there are those who accept 
the ''directive tendencies" and "conscious attitudes" as 
phases or even contents of consciousness, but they believe 
that they are ahvays attached to sensory, or imaginal fac- 
tors and do not exist alone in consciousness. Third, there is 
a smaller group of psychologists who believe in the existence 
of a "pure thought content," independent of any sensory or 
imaginal content. 

The Neural Basis of Reason. — We are not yet in posses- 
sion of sufficient anatomical and physiological knowledge of 
the brain to be able to point out any specific cortical areas 
as thought centres. There are in the cerebrum very consider- 
able areas which are not involved so far as we know in the 
reception of sense-impressions, or in the sending out of motor 
impulses. Two large areas in each hemisphere of the brain, 
one in the frontal region and one in the occipito-parietal 
region, commonly known as the associational areas, or Flech- 
sig centres, have been thought to be involved in the higher 
thought processes. The frontal associational area especially 
has been considered as the higher centre or thought centre. 
This region is more highly developed in man than in any other 
animal, which fact has led to the belief that the frontal con- 
volutions are the thinking areas. This is probably a good 
guess, although it is too general in character to be of any 
value. Without doubt, these associational a,reas contain 



REASONING 355 

neurones which mediate between the different sensory areas, 
and between the sensory areas and the motor areas, and so 
form centres of interconnection in the cortex. But just what 
particular brain centres are active in moments of ratiocination 
we do not know. It is very probable that the thinking 
process makes use of very wide-spread regions of the cortex, 
even including the sensory areas. 

In cases where thought is not required to respond to a 
given presentation, reactions take place immediately and the 
nervous pathway from stimulus to response may be con- 
ceived as relatively simple and direct. But in other cases 
where thought is needed to bring the light of past experiences 
upon the present situation so that an intelUgent response 
may be made, the impulses started by the stimulus may be 
conceived as shunted, or drained off, into larger areas than 
those involved in direct response. These larger areas may 
be thought of as higher centres in the sense that their activi- 
ties correspond to larger and more highly systematized bodies 
of. knowledge, meanings, and relationships, gained through 
past experience. When we realize that reasoning is not a 
separate kind of consciousness, or the immediate awareness 
of a given situation, but rather is the present consciousness 
augmented by the significance or essence of past experi- 
ences, then we shall cease to look for separate brain centres 
for thinking. On the other hand, we should expect the neural 
counterpart of reasoning to be a larger brain action, involving 
not only the limited neural action corresponding to the pres- 
ent-moment presentation, but also the centres correspond- 
ing to past perceptions, memories, and images. As larger 
and larger units of experience are awakened and incorporated 
into the present-moment consciousness, ever-widening waves 
of neural excitation must sweep over the cortex as the neural 
counterpart of thought. We must not forget, however, that 
such a conception of the matter is merely a conjecture with 
a very meagre body of fact to support it. 



CHAPTER XVI 
AFFECTION AND FEELING 

So far we have been engaged in the task of analyzing and 
describing the mental states which give us our knowledge of 
the outer world of objects and relations. Sensations, per- 
ceptions, memories, judgments, concepts, and reasoning proc- 
esses — all these forms of cognitive consciousness may be 
said to have an objective reference, in that they refer to 
things and relations in the outer world. We have now to 
examine those forms of consciousness which have subjective 
reference. We not only know objects and their relations but 
at the same time we are subjectively affected by them. The 
mental states containing certain attitudes aroused in us 
by the objects of our knowledge are called feelings. Thus a 
sensory experience may be pleasing or displeasing; we may 
Hke or dislike a particular person; feel joy or sorrow in the 
contemplation of certain facts; experience annoyance or anger 
in the action of a friend, etc. In its broadest psychological 
meaning, feeling is the term which denotes all those states of 
consciousness which are characterized predominantly by our 
affective attitudes. 

Affection. — -Feelings are complex conscious states consist- 
ing in sensory or ideational elements and the purely affec- 
tive consciousness which these cognitive or ideational experi- 
ences arouse. When the affective consciousness predominates, 
the total conscious experience is called a feehng. The 
characteristic factor in feeling is affection. Affection is a 
unique and elementary content of consciousness always accom- 
panying some cognitive process and never existing alone. 
Although affection is aroused by and accompanies cognition, 
it is easily distinguishable from the cognitive elements. Af- 

356 



AFFECTION AND FEELING 357 

fection manifests itself in two qualities which stand in direct 
opposition to each other. A sensation, perception, memory, 
or other cognitive state may be (i) agreeable or (2) disagree- 
able when we experience it; i. e., we are agreeably or dis- 
agreeably affected by it. Agreeableness and disagreeableness 
are the two elementary forms of affection. Pleasantness 
and unpleasantness are terms also used to designate these 
two forms of affection. 

Some cognitive processes are pleasantly and some are 
unpleasantly toned, while some appear to be neutral in affec- 
tive tone. With a medium intensity of stimulation the 
taste of sugar is pleasant, the taste of quinine is unpleasant, 
while certain other tastes are indifferent. Memories , and 
ideas, judgments and reasons, in short, all forms of cogni- 
tive process may be pleasantly or unpleasantly toned. Some 
psychologists have been willing to stand for the statement 
that every cognitive process is accompanied by affection in 
some degree of intensity — that in the case of the apparently 
indifferent cognitive experiences the affection is so low in 
intensity that it is below the threshold of consciousness and 
so does not reveal itself to introspection. If, however, we 
credit the report of introspective observation, we are forced 
to admit that many cognitive experiences are neutral so far 
as affection is concerned. 

The Nature of Affection. — When we go to the text-books 
for an answer to the question, What is the real nature of affec- 
tion? we get a variety of answers. Some psychologists look 
upon affection simply as an attribute of sensation, just as 
intensity and duration are attributes. They refer to affection 
as the "pleasure-pain tone" or the "affective tone" of sensa- 
tion. They think of affection as belonging to sensation, never 
as a separate affective process. The objection to this view 
lies in the fact that affection is an independent variable in its 
relation to sensation. It may or it may not accompany a 
given sensation, and some sensations are without aft'ective 
tone altogether. Now, an attribute does not usually act in 



358 PSYCHOLOGY 

this way. If the intensity or duration of a sensation should 
be reduced to zero the sensation itself would disappear. 
This is apparently not true when its affective tone reduces to 
zero. Evidently affection is something more than an attri- 
bute of sensation. Moreover, affection has its own attributes 
— quality, intensity, and duration. 

Other psychologists consider affection as a form of sen- 
sation akin to the organic sensations. The organic sensations 
are vague and undifferentiated, poorly localized, and have 
few, if any, definite qualities. They are, therefore, like the 
affective experiences. Pleasantness and unpleasantness may 
be, it is thought, organic sensations that are too indefinite 
and too diffuse for clear cognition. They are accordingly 
submerged or undeveloped sensations. Against this conten- 
tion we may mention the fact that affection is found accom- 
panying all kinds of sensations from the lowest organic sensa- 
tion to the most highly developed visual sensations. This 
fact indicates that affection is not another kind of sensa- 
tion but a unique conscious content different in quality from 
the sensory content. 

Some of the earlier writers took an intellectualistic view 
of affection. Hegel, for instance, held that affection is an 
obscure kind of knowledge. Wolff thought it to be an intui- 
tive knowledge of the state of the body. In this latter view 
the intellectuahstic view of affection changes into a sensational 
view. Another and more definite form of the intellectualistic 
view of affection is that which considers affection as the rela- 
tion of ideas, or sensations, to each other. In aesthetic experi- 
ences the harmony and balance of parts — the consonance of 
tonal sensations — are pleasing, while lack of harmony and 
balance of parts, and dissonance of tonal sensations are dis- 
pleasing. The experience of relationship is a cognitive, not 
an affective process. The affective consciousness is something 
added to the cognitions. Although affection may be in some 
cases dependent upon the relation of sensations and ideas 
to each other, it is not itself a relation. Furthermore, affec- 



AFFECTION AND FEELING 359 

tion is not always dependent upon the consciousness of re- 
lationship, it may also be connected with single sensations 
and ideas. 

We have so far rejected the views (i) that affection is an 
attribute of sensation, (2) that it is a kind of sensation, (3) 
that it is an obscure kind of knowledge, (4) that it is a rela- 
tion. What, then, is its real nature? In the opinion of the 
author the most satisfactory answer is that affection is a 
unique and elementary mental content, different from, but 
co-ordinate with, cognitive content. It is a new form of con- 
sciousness which, while dependent upon cognition, neverthe- 
less plays its own particular part in our conscious life. 

Kinds of Affection. — ^We have already stated that there 
are two elementary and opposite forms of affection: pleasant- 
ness and unpleasantness. All psychologists do not concur in 
this statement. Wundt, for instance, believes that there 
are in addition to pleasantness and unpleasantness two other 
pairs of opposing affections: excitement and calm, and strain 
and relaxation. This view is known as the "tridimensional 
theory of affection." He holds that these six forms of affec- 
tion are not simple or elementary — that each has a large num- 
ber of different qualities. There are accordingly many kinds 
of pleasantness, unpleasantness, etc. Titchener in his "Text- 
Book of Psychology," pp. 250-7, attacks Wundt's theory 
very vigorously. In the first place he points out that while 
pleasantness and unpleasantness are in every essential way 
opposites in nature, neither excitement and calm, nor strain 
and relaxation manifest in a true sense any such relation. 
On the other hand, relaxation is the minimum degree or lack 
of strain. Likewise calm cannot be thought of as the real 
opposite of excitement, but rather as the lack of excitement. 
Moreover, excitement and calm, or tension and relaxation may 
themselves be pleasantly or unpleasantly toned. How can 
this be if they are true affections? Wundt holds that the 
character of affection depends upon the attributes of sensa- 
tion. Pleasantness and unpleasantness depend upon the 



360 PSYCHOLOGY 

intensity of sensations. Moderate intensities are pleasing 
while very low or very high intensities are unpleasant. Excite- 
ment and calm depend upon the quality of sensations, strain 
and relaxation depend upon the temporal attribute. If 
sensations are too slow or too rapid in developing, we ex- 
perience strain, but if their time aspect is normal, we experi- 
ence relaxation. Titchener thinks this view inadequate, in that 
it fails to take account of the spatial attribute of sensation. 
What kind of affection corresponds to the variations in our 
experiences of space? If the other attributes of quahty, 
intensity, and duration have definite affective qualities depend- 
ing upon them, why is extensity lacking in this respect? 

That we have experiences that may be called excitement 
and calm, strain and relaxation, cannot be doubted. Many 
psychologists, however, believe that these experiences are 
cognitive and not affective in nature. Strain and relaxation 
are without doubt sensory experiences of the conditions 
of the muscular system (kinaesthetic sensations). Excite- 
ment and calm seem to consist in the awareness of the vivid- 
ness and rate of change in our mental states plus certain 
kinaesthetic sensations. When excited our respiration and 
heart actions are disturbed. The normal rate of the physi- 
ological processes is changed and the general activity of con- 
sciousness is increased. The awareness of these changes 
constitutes the major part of the experience. It cannot, 
therefore, be considered as affective in character. Affection 
may, of- course, accompany these cognitive processes, but the 
excitement is not the affection. In view of these considera- 
tions, we are forced to abide by our earlier analysis of aft'ec- 
tion into pleasantness and unpleasantness as the two elemen- 
tary forms of affection. 

Attributes of Affection. — The attributes of affection are 
quality, intensity, and duration. We have found that the 
fundamental qualities of affection are pleasantness and un- 
pleasantness. In much the same way that one sensation 
differs from another sensation in quality, the affection pleas- 



AFFECTION" AND FEELING 36 1 

antness differs from the afifection unpleasantness. Whether 
there is only one quality of pleasantness or unpleasantness, 
or whether there are many qualities, is a question that has 
not yet been settled among psychologists. Affection varies 
in intensity. An experience may be shghtly pleasant or very 
pleasant. The same is true of unpleasantness. Affection 
also varies in duration. It may be momentary or it may 
continue for longer periods. 

Adaptation. — Experiences tend to lose their affective char- 
acter when long continued. Objects and events that are 
markedly pleasant or unpleasant at first, become indifferent 
later. A pleasing bit of color or a beautiful landscape will 
in time become indift'erent to us if we continue to experience 
it. Likewise a disagreeable odor or the unpleasant man- 
ners of a friend will under the same conditions fail to af- 
fect us. 

Affection and Sensation. — Since affection is dependent 
upon the cognitive processes, we shall expect to find it related 
in certain ways to variations in these processes. First of all 
we may note that the different modes of sensations do not 
arouse affection in the same degree. The more highly special- 
ized sensations appear to have less aft'ection than those that 
are not so highly specialized. For instance, the visual sen- 
sations are not as pleasing or displeasing as the olfactory or 
gustatory sensations, while the organic sensations have the 
most intense affections. Within the modes themselves affec- 
tion varies with the quality, intensity, and duration of sensa- 
tions. With the normal intensity and duration the qualities 
of some sensations are inherently agreeable or disagreeable. 
Thus some of the spectral colors are more agreeable than 
others. Tones of medium pitch are more pleasing than those 
of very high or very low pitch. Sweet is agreeable while 
bitter is disagreeable. Why some qualities of sensations 
are agreeable and some disagreeable is a question to which 
we shall return later. 

Aft'ection varies with the intensity of sensations. Sen- 



36? PSYCHOLOGY 

sations that are normally agreeable pass over into disagreeable- 
ness when the intensity becomes high. A tone of moderate 
intensity may be pleasing, but if the tone is increased in 
intensity it becomes disagreeable. With a continually in- 
creasing intensity most stimuli finally reach a point where 
the pain nerves are stimulated and the sensation of pain is 
aroused. The pain must not, however, be confused with 
disagreeableness of the original sensation. Sensations that 
are normally disagreeable become increasingly disagreeable / 
when their intensities are increased. All sensations of very ^ 
weak intensities appear to be disagreeably toned, but the 
affective tone may be due to the difficulty of attending to 
sensations of low intensities. 

Sensations that are normally agreeable may become dis- 
agreeable if their durations are either too brief or too long. 
As in the case of very low intensities of sensations, very short 
durations may owe their disagreeableness to the processes 
of attention in these cases. Agreeable sensations have a 
definite duration during which their agreeableness is at its 
maximum. When adaptation sets in agreeableness passes 
into the region of neutrality and then into disagreeableness. 
Normally disagreeable sensations appear to remain disagree- 
able for all periods. They may, however, become less dis- 
agreeable through adaptation. 

Pain and Affection. — The fact that pain-sensations are in 
almost ah cases disagreeably toned has contributed to the 
popular belief that pain is disagreeableness itself. The ex- 
pression "pleasure-pain tone of sensation," has been very 
widely used even in psychology. Pain, however, is not an 
affection, but a sensation. It is true that it is usually accom- 
panied by the affection of disagreeablenes, but in a few cases 
where the pain-sensation possesses a very low degree of 
intensity it may be neutral or even agreeable. Slight stimu- 
lation of certain parts of the body by an electric needle give 
rise to fine pain-sensations that are of an agreeable character. 
Charged beverages owe their agreeableness partly to the 



AFFECTION AND FEELING 363 

delicate pain-sensations aroused mechanically by the presence 
of gas in the beverages. 

Pain, then, offers no exception among sensations in its 
relationship to affection. Popular thought does not easily 
accept this view, for the reason that we do not ordinarily 
consider a stimulus painful until it is accompanied by dis- 
agreeableness. Hence the confusion in ordinary thought 
between the sensation of pain and the affection of disagree- 
ableness. 

Aflfection and Perception. — Since the perception of an 
object includes the presentation of several sensory qualities 
the affective tone accompanying the perception is the com- 
plex of the affections belonging to the several sensations 
within the perception. Some aspects of the total object may 
be pleasing while others may be neutral or displeasing. 
Whether the resulting affection really is a complex made up 
of parts, or whether it is a unitary and unanalyzable content 
accompanying the total perception process, is a question for 
future determination. Do the different sensations pool 
their affections, or is there a single affection depending upon 
the perception ? 

Affection and the Ideational Processes. — Not only does 
affection accompany sensory elements and perceptions, it also 
accompanies ideational processes. Memory, imagination, 
and reasoning processes may be agreeable or disagreeable 
in themselves. But since these ideational processes take place 
in an organism that is always receiving sensory stimuli of 
some kind, either from the outer world or from the organic 
processes within, it is sometimes difficult to determine how 
much of the total affection is due to the ideational process 
and how much is due to the sensory experiences. We cannot, 
however, question the fact that the higher and centrally in- 
itiated processes are in themselves affectively toned. A 
memory act may be agreeable or disagreeable. It may or 
it may not have the same quality of affection that belonged 
to the original experience. Oftentimes experiences that are 



364 PSYCHOLOGY 

originally pleasing are, when remembered, decidedly unpleas- 
ant. Whether a memory act is pleasant or unpleasant is 
determined by the relation of the recalled experience to the 
contents of consciousness at the time. If it stands in opposi- 
tion to our present purposes, desires, and ideas, it will be 
unpleasantly toned, but if it is in conformity to them it will 
be pleasantly toned. Images and concepts also conform to 
this general rule. It is doubtful whether affection possesses 
a memory of its own. Can we image and reinstate our 
affections as we do our cognitive states? We can remember 
that certain past experiences were agreeable or disagreeable, 
but this process is purely cognitive, not affective. Memory 
involves imagery, and images are possible only as cognitive 
products. Affection is always a first-hand product, arising 
fresh from the nature of the cognitive processes at the present 
moment and never the image or reproduction of a previous 
state. 

Over and above the affective states which accompany 
the separable cognitive elements in the intellectual process, 
a further affective coloring may adhere to the thinking 
process itself. Here the same general principle, which we 
found governing the affective states in memory and imagina- 
tion, holds in the processes of thought. Reasoning processes 
which aid our purposes, interests, and desires, are agreeably 
toned, while those which oppose them are disagreeably toned. 

Affection and Bodily Expressions. — Attempts have been 
made to, find the characteristic bodily reactions which are 
connected with agreeableness and disagreeableness — such 
bodily reaction as changes in circulation, respiration, secre- 
tions, digestion, and involuntary movements. Changes in 
respiration during both agreeable and disagreeable experiences 
have been studied by means of the pneumograph — an instru- 
ment which records the rate and depth of breathing. Varia- 
tions in the pulse have been recorded by the sphygmograph, 
and changes in the volume of the arm or other members 
of the body by the plethysmograph. The results of these 



AFFECTION AND FEELING 3(35 

studies of the bodily expressions connected with pleasantness 
and unpleasantness are conflicting. Changes in respiration, 
heart-beat, gland activities, and involuntary movements have 
been observed during the experiences of pleasantness and 
unpleasantness. Breathing may be increased or decreased 
in rate and depth, the pulse may be quickened or slowed, 
strengthened or weakened, etc., but no one set of these 
changes is found to take place uniformly with either one of the 
affections. More recently the galvanometer has been used 
to detect the presence of electrical currents in the body 
during affective experiences. The discovery of these cur- 
rents in the body was thought to be the beginning of a new 
era in the study of the expressions of affective and emotional 
states. Cognitive activity was found to be accompanied by 
only slight electrical changes while affective states manifested 
their presence much more markedly. But when we consider 
that muscular activity may produce electrical changes similar 
to those found accompanying affective states we must con- 
clude that electrical phenomena are not distinctive marks 
of affective expression. Moreover, these electrical changes 
do not differ in character for the two forms of affection. 
Later investigations indicate that the action of the sweat- 
glands have something to do with the electrical changes 
recorded by the galvanometer. Increased humidity of the 
bodily surfaces would certainly favor the passage of electri- 
cal currents from one part of the body to another. 

In regard to the grosser form of expression and behavior 
accompanying affective states, ordinary observation has lit- 
tle difficulty in detecting the difference in the facial expres- 
sions and bodily attitudes which attend the affective state 
of pleasantness and those which attend the affective state 
of unpleasantness. We know immediately when our friends 
are pleased and when they are displeased. In a general way 
we may say that pleasurable experience tends to bodily move- 
ments of expansion and approach, while unpleasant experi- 
ences tend to movements of contraction and withdrawal. 



366 PSYCHOLOGY 

There can be no question but that all the vital processes, even 
those of assimilation, secretion, and excretion, are influenced 
during affective experiences; but, beyond the very general 
statement which we have already made, we are unable to 
formulate any law which governs the affective bodily ex- 
pressions. 

Neural Basis of Affection. — Sensations depend upon the 
action of specific nerves and brain centres. There are, how- 
ever, no special end-organs and brain centres for pleasantness 
and unpleasantness. What, then, is the neural basis of affec- 
tion ? We have no exact detailed knowledge to offer in answer 
to this question. We must, therefore, resort to theory. It 
seems probable that affection depends upon the mode in 
which neural activity goes on in any particular part of the 
nervous system, or upon the way in which the neural activity 
in any one part affects the other parts of the nervous system 
or the nervous system as a whole. Normal and efficient 
reaction of the neural mechanism in any particular segment 
corresponds to pleasantness, while excessive or inefficient re- 
action corresponds to unpleasantness. This would explain 
the disagreeable character of very high and very low sense 
intensities. 

We must admit that this principle is difficult to apply in 
cases where unpleasantness is due either to the quality of 
sensations or to ideational processes. Why, for instance, is 
the moderate intensity of bitter unpleasant? Or why is 
the perfectly clear and definite thought of a friend's disloyalty 
unpleasant ? In the case of the sensation bitter we may sup- 
pose that the nerve-tissues involved are not adapted to the 
stimulus — that the nerve-currents caused by the stimulus are 
of such a nature that they meet resistance in the nervous 
tissue of the sense pathways and centres. In the case of 
the thought of the friend's disloyalty the resistance would be 
found in the association paths and centres. Thus the theory 
of resistance may be applied to all cases of affection ac- 
companying both sensory and ideational processes, Ziehen 



AFFECTION AND FEELING 367 

proposes such a theory. He holds that the normal and effi- 
cient discharge of nerve-currents from any part of the brain, 
along paths of projection, or paths of association, is the neural 
counterpart of pleasantness, while any obstruction of such 
discharge is the counterpart of unpleasantness. In short, 
pleasantness goes with facilitation and unpleasantness with 
inhibition of neural activity. It is interesting to compare 
with this physiological theory of affection the old intellec- 
tualistic theory that pleasantness is the awareness of the 
harmonious co-operation of ideas, and that unpleasantness is 
the awareness of the conflict between ideas — in other words, 
that affection is brought about by the facilitation and inhibi- 
tion of ideas among themselves. Since we are committed to 
the hypothesis that every form of consciousness has a neural 
basis of some kind, we must, therefore, consider the neural 
as well as the mental conditions under which affection arises. 
The conditions of resistance affecting the mode of activity 
in nerve pathway and centres may then be taken as the 
neural basis of affection. Many other theories have been 
proposed. Bain's statement of the case may be translated 
into neural terms. He says that "states of pleasure are con- 
nected with an increase, and states of pain with an abatement, 
of some or all of the vital functions." This, of course, is true 
in many instances, but it does not always hold. Cases may 
be found where pleasure is the accompaniment of lessened 
vital functions. 

Titchener thinks that the free sensory nerve-endings found 
throughout the different tissues of the body are the peripheral 
organs of affection. They represent, he thinks, "a lower level 
of organic development than the specialized receptive organs, 
or organs of sense. Had mental development been carried 
further, pleasantness and unpleasantness might have become 
sensations — in all likelihood would have developed into a num- 
ber of sensory qualities." Back of this hypothesis lies the 
theory that sensations and affection have both developed from 
a common mental ancestor — a kind of undifferentiated con- 



368 PSYCHOLOGY 

sciousness. He says that "the affections appear — not ex- 
actly as undeveloped sensations — but at any rate as men- 
tal processes of the same general kind as sensations, and as 
mental processes that might in more favorable circumstances 
have developed into sensations." 

The exact function of the free nerve-endings is in dispute. 
We have in our treatment of sensation considered them as 
sense end-organs whose stimulation results in pain. There 
is nothing impossible, however, in the supposition that there 
are undifferentiated free nerve-endings within the tissues of 
the body which may give rise to certain affective experiences. 
It is, however, difficult, to see how the affections accompany- 
ing ideational processes can be accounted for by such nerve- 
endings. 

Certain writers connect affection with the action of special 
cortical centres in the brain, others, like Meynert, connect 
affection with the nutritive condition of the brain. But 
where definite facts are wanting it is useless to attempt to 
evaluate these theories. Lehmann considers pleasantness cor- 
related to the proper balance between the supply and the 
expenditure of energy by the nerve-cells in the brain; while 
unpleasantness is the correlate of an excess of expenditure 
over supply. Very intense stimuli are disagreeable because 
they overwork the brain-cells and call for a greater expendi- 
ture of nervous energy than can be supplied by the nutritive 
process in the centres involved. Miinsterberg suggests what 
he calls the "action theory" of affection. Pleasantness is 
the correlate of central brain activity which is starting bodily 
movements of approach, while unpleasantness is the correlate 
of central brain activity which is starting movements of with- 
drawal. Affection, therefore, is the conscious accompani- 
ment of central brain processes connected with the arousal 
of movement impulses. 

The Significance and Function of Affection. — When we 
review the facts of our affective consciousness we see that 
we are justified in believing that pleasantness is correlated 



AFFECTION AND FEELING 369 

with those conditions both within and without the organ- 
ism which make for its welfare; while unpleasantness is 
correlated with those conditions that menace its welfare. 
In the main whatever is immediately beneficial is agreeable 
and whatever is immediately harmful is disagreeable. In 
a complex organism Hke that of man the application of this 
principle meets with many difficulties for the reason that 
sometimes what is beneficial to some one phase of his existence 
is harmful to another, and what is helpful for the immediate 
moment is detrimental in the long run. Affection, then, 
may be looked upon as an index of the immediate conditions 
that are beneficial or harmful to the organism. 

There seems to be no doubt of the fact that pleasantness 
determines appetition — the tendency to hold to certain stimuli 
and continue certain experiences, and that unpleasantness 
determines aversion — the tendency to withdraw from cer- 
tain stimuli. The reactions involved in appetition and 
aversion are the most fundamental and, significant selective 
reactions of the organism. It may be true that in man's 
higher development some of his reactions are not determined 
by the agreeable or disagreeable, but in his primitive forms of 
behavior, at least, he seeks the pleasant and avoids the 
unpleasant. If, now, the pleasant is connected with the 
beneficial and unpleasantness with the harmful, we can see- 
of what far-reaching biological significance the affective con- 
sciousness must have been in organic development. Organ- 
isms which in the beginning sought the pleasant must have had 
a tremendous advantage over those which did not. To the 
question as to how the connection between the beneficial 
and the pleasant experiences was established we are unable- 
to offer an answer in psychology. That is a question which 
the biologists have not yet settled. Were the first organisms, 
as likely to seek stimuli giving unpleasant experiences as those 
giving pleasant experiences? Did natural selection by 
killing off those who sought the unpleasant establish the- 
tendency in the race to seek the pleasant ? If this is true 



370 PSYCHOLOGY 

then we must suppose that the relation between the pleasant 
and the beneficial and between the unpleasant and the harm- 
ful stimuli were already established in the very beginning. 
Some psychologists, perhaps, would prefer to disregard con- 
sciousness altogether as a factor in evolution. Natural se- 
lection would then preserve those organisms which happened 
to seek beneficial stimuli and eliminate those that happened to 
seek harmful stimuli. Consciousness in such a scheme 
would have nothing to do with organic development. In 
this case the tendency to seek the beneficial and avoid the 
harmful must have grown up through natural selection inde- 
pendently of the consciousness of pleasantness and unpleasant- 
ness. It is, however, inconceivable that so important a fac- 
tor as consciousness has had nothing to do with behavior. We 
cannot give up the principle previously postulated, viz. : that 
the affective states of pleasantness and unpleasantness have 
been and still are in a large measure efiicient factors in the 
struggle for existence. We are willing, therefore, to accept 
the hypothesis that beneficial stimuli were from the very 
first capable of giving the experience of pleasantness and 
harmful stimuli the experience of unpleasantness. 

Feeling. — While feeling is a complex mental state con- 
taining cognitive elements, the predominating character of 
the experience is given to it by its affective components. Pain, 
for instance, although a sensation, is often properly spoken of 
as a feeling, because the total experience is predominantly 
affective. Hunger too may be referred to as a feeling when 
we mean to include the affection accompanying its sensory 
process. Many of the organic sensations are commonly con- 
sidered to be feelings because the sensory quaKties in the 
experiences are so vague and unclear that, failing to occupy 
attention, they allow the affective consciousness to outweigh 
them in the total experience. Not only do sensory elements 
form nuclei for feelings, but memories, images, and trains 
of thoughts are oftentimes so deeply submerged in affective 
consciousness that the experiences may be termed feelings. 



AFFECTION AND FEELING 371 

Since sensory and ideational processes of various varie- 
ties and in many degrees of intensities and duration may 
combine with the different qualities of affection, it is evident 
that the number of different feelings that the human mind 
can experience is infinitely great. They may vary from the 
very simple feelings involving only a single sensation, percept, 
idea, or thought to the most complex feelings involving 
highly compUcated combinations of sensory and ideational 
elements and mental activities. The feeling of hunger, of 
pain, or that aroused by a pure spectral color or by the thought 
of honesty are simple feelings, while that aroused by a sym- 
phony, the Sistine Madonna, or by the tragedy of "Hamlet" 
are very complex feelings. Feelings may also vary from the 
relatively pure to those that are highly mixed. All the 
elements in a situation may arouse the same kind of affection. 
On the other hand, some of the elements may be disagreeable 
while the others may be agreeable. The resultant feeling in 
the first case is pure while the feehng in the second case is 
mixed. The feeling aroused by a beautiful landscape is pure. 
Every part of the whole — the several objects, colors, etc. — 
is agreeable, as is also the synthesis of these parts into the 
whole. But the feeling which stirs us when we contemplate 
Shakespeare's tragedy "Hamlet" is a mixed feehng; for while 
some of the separable contents of our thought are unpleasantly 
and some pleasantly toned, the artistic combination of the 
parts into a whole may produce a decidedly pleasant effect. 
It is evident that the complex feelings may be either pure 
or mixed accordingly as they contain affections of the same 
or of different quaUties. The simple feeUngs are always pure 
feelings. 

Classification of Feelings.— The classification of the feel- 
ings based only upon the quaHty of affection which enters into 
them gives just two kinds of feelings: Pleasant and un- 
pleasant feelings. But if we employ other bases of classifica- 
tion, many kinds of feelings may be made out. In view of 
the great number of combinations that may occur between 



372 PSYCHOLOGY 

the elements of affection and the different qualities and 
intensities of sensations and of ideational processes, it is 
impossible to make any adequate classification of the feelings. 
We can suggest only a few very general divisions. 

As we have already seen, if we think of the degree of com- 
plexity into which the component parts of feeling enter, 
feelings may be simple or complex; or pure and mixed if 
we consider the homogeneity or heterogeneity of the affec- 
tion qualities which enter into the combination. 

Certain vaguely localized and obscure organic sensations 
have sometimes been spoken of as sensus communis or "com- 
mon feelings." These sensations arise from changes in blood- 
supply in the capillaries about nerve-endings, from the physi- 
ological condition and action of heart, lungs, glands, and other 
internal organs — in short these sensations constitute the 
vague awareness we have of the condition of inner organic 
processes. This awareness is never raised to definite and 
clear presentations of sense and for this reason the sensa- 
tions referred to appear to be almost entirely affective in 
nature. They do possess affective tone and the mixture of 
obscure sensations and affection result in the common feelings. 
Feelings of well-being, of high spirits, of depression, of gloom 
and despondency belong to this class of common feelings. 
Although they usually remain in the background of conscious- 
ness, they may give tone and color to the entire stream of 
consciousness. They are not only important in determining 
our moods but they also contribute very largely to the con- 
sciousness of self. Temporary and often slight functional 
disturbances in the vital processes may result in a personal 
"feeling of strangeness" or a "feeling of not like ourselves" 
without our knowing why. The common feelings are differen- 
tiated from the feeling which arises in connection with the 
special senses, or with the ideational process, by the obscure- 
ness of their cognitive elements. 

Feelings may be classified into sensuous and intellectual 
feelings accordingly as their cognitive contents .result from 



AFFECTION AND FEELING 373 

the sensory or the ideational processes. But since ideational 
processes depend upon and involve sensory elements this 
classification is not a very valuable one. 

If we were to classify the feelings according to the nature 
of the cognitive states which enter into them, the list of feel- 
ings would be as long as that of the cognitive states them- 
selves. Some of our presentations and trains of thought, 
however, are especially prolific in producing affective states. 
^Esthetics, ethics, social relationships, and religion involve 
presentations, ideas, and thoughts which enter into feeling 
complexes. It is suggested, therefore, that we classify feelings 
into (Esthetic feelings, ethical feelings, social feelings, and relig- 
ious feelings. This, however, is a very partial and incom- 
plete classification. There are many other cognitive experi- 
ences which are capable of arousing affections. 

Mood. — We often find that for considerable periods of 
time the stream of consciousness is permeated by a more or 
less persistent affective tone. All our presentations and 
thoughts are temporarily colored by a certain affective atti- 
tude. This predisposition to feel in a certain way is known 
as mood. For hours after receiving a bit of good news we may 
be dominated by the feeling of cheerfulness. Even disagree- 
able experiences are transformed and lose their irritating 
character under the spell of this mood. On the other hand, 
bad news or an especially irritating experience may leave us 
with the "blues." Moods are not only the after-effects of 
past events and past feelings, but they may be induced by 
intra-organic conditions. Blooming health predisposes to 
cheerfulness, while indigestion or other physiological dis- 
turbances may depress us and make the whole world seem 
out of joint. Sometimes we pass from one mood to another 
very quickly, at other times the change takes place very 
slowly. 

Temperament. — While mood is a temporary disposition 
to feel in a certain way, temperament is a fixed and permanent 
predisposition toward a definite form of affective response. 



374 PSYCHOLOGY 

Individuals differ markedly in this respect. Some are so 
constituted that everything appears in a gloomy and melan- 
choly light, while others are constitutionally predisposed to 
view everything in the brightest hues. These differences 
in temperament are probably due to hereditary factors and 
represent in each individual permanent tendencies in his 
feeling attitudes. A very old and well-known classification 
of temperaments divides them into four classes accordingly 
as their feeling responses are quickly or slowly aroused and 
whether they are intense or weak in character. These forms 
of temperament are choleric, melancholic, sanguine, and 
phlegmatic. 

The choleric temperament has quickly aroused and 
intense feelings, the melancholic has slowly aroused and 
intense feelings, the sanguine has quickly aroused and weak 
feelings and the phlegmatic has slowly aroused and weak 
feelings. 

Emotions. — There are certain complex and mixed feelings 
possessing a high degree of intensity and vividness, which 
are known as emotions. They might be referred to as feel- 
ings of agitation. They are conditioned by a series of wide- 
spread and diffuse organic excitations, conflicting instinctive 
impulses, and habitual types of reaction. On the cognitive 
side they contain the perception or ideation of certain excit- 
ing objects and events plus a mass of kinaesthetic and organic 
sensations which are aroused by the organic excitation and 
the conflicting instinctive impulses and reactions. The af- 
fective states accompanying these various cognitive states en- 
tering into the total complex are, therefore, numerous and 
conflicting. In all the other feehngs the stream of cognitive 
consciousness is not especially disturbed — the various processes 
of presentation and currents of thought go on more or less 
smoothly and without marked interruption, but in emotions 
there is a sudden stoppage in all the avenues of mental activ- 
ity. Especially is there a blocking of the higher cognitive 
activities. We are seized, as it were, by emotions. The 



AFFECTION AND FEELING 375 

neural excitement caused by an emotional object or event 
fails to be adequately drained off through the usual channels 
of adjustment. As a consequence the nervous energy aroused 
is turned back into the organism and diffused throughout 
the organic and motor pathways, thereby causing a condi- 
tion of conflicting bodily impulses. Anger and fear are 
typical emotions. Since we shall return to the study of 
emotions in the next chapter, we shall give no more space to 
their consideration here. We have mentioned them only 
to point out their place among the feelings. 

Sentiments. — Sentiments are relatively permanent feel- 
ings which grow up around more or less complete systems of 
ideas and intellectual processes. A sentiment might be called 
a frame of mind colored and supported by affective conscious- 
ness. Baldwin's "Dictionary of Philosophy and Psychology" 
defines sentiments as "emotional dispositions having refer- 
ence to an object or class of objects represented by a more 
or less complex system of ideas." They are, however, milder 
and more enduring feelings than emotions. They are feel- 
ings which are based upon and include a more rational cogni- 
tive process than emotions. They vary, however, in this 
respect, sometimes more and sometimes less of the rational 
element being present. They may at times under certain 
circumstances rise to the same intensity and take on the 
irrational and agitating character of emotions. Love, for 
instance, is both a sentiment and an emotion. As a sentiment 
it includes a rationalized system of ideas and the affective 
tone which attaches to the ideas. As an emotion these 
ideas temporarily sink into the background while we are 
thrilled in every nerve by the object of the emotion. Friend- 
ship is a typical sentiment. Here we find the mental pres- 
entations of the personal virtues and characteristics of the 
object of friendship and the experienced conformity of these 
characteristics to certain ideals which have been formulated 
and fixed in our minds. A sentiment is not experienced in 
its entirety at any one moment; it follows in its activity the 



376 PSYCHOLOGY 

sequence of ideas which centre about its object and so only- 
one phase of the sentiment is active at a time. In so far, 
however, as we are able to unify all the various ideas into a 
single concept, the sentiment too may be unified into a momen- 
tary experience. 

Since sentiments form about relatively stable centres of 
ideas and intellectual processes, we may expect to find most 
authorities classifying them according to certain fields of 
experience in which we have established ideals, or norms. We 
have, for instance, ideals of truth, of right, of beauty, and of 
the Absolute. Ideational constructions which are conform- 
able or non-conformable to such ideals would constitute the 
bases for the different kinds of sentiments. Accordingly, 
sentiments are divided into (i) intellectual or logical, (2) 
ethical or social, (3) (esthetic, and (4) religious sentiments. 
Among intellectual sentiments may be mentioned those of 
belief and disbelief, of truth and falsehood, of agreement 
and contradiction. The ethical sentiments include those of 
friendship, hate, pride, freedom, and gratitude. The aesthetic 
sentiments include the sentiments of beauty and ugliness, of 
sublimity and tragedy. Among the religious sentiments 
are those of awe, reverence, faith, and remorse. 

Passion. — The term passion is very loosely used in ordi- 
nary speech. Sometimes it may refer to a sentiment; as when 
we say that one has "a passion for painting." Sometimes 
it refers to a strong and uncontrolled emotion. In psychology 
the second usage is prevalent. But really no sharp line be- 
tween emotions and passions can be made out. We speak 
of an emotion as a passion when it takes possession of us 
to such an extent that all our powers of voluntary control are 
inhibited. 



CHAPTER XVII 
EMOTIONS 

In the preceding chapter we said that emotions are highly 
complex feelings. While a simple feeling manifests only a 
single cognitive element and its affective accompaniment, 
emotion, on the other hand, is a highly complicated and 
diffused reaction of the whole conscious organism in which 
many cognitive and affective elements are fused together. 
Before elaborating this theory of the emotions we may prof- 
itably examine a very suggestive theory of emotions proposed 
in this country by William James and in Europe by C. Lange, 
professor of medicine in Copenhagen. These writers, working 
independently of each other, came to practically the same con- 
clusions. For that reason the theory is known as the " James- 
Lange Theory of Emotions." 

James-Lange Theory of Emotions. — Speaking of the emo- 
tions of grief, fear, and anger, James says: "Our natural way 
of thinking about these coarser emotions is that the mental 
perception of some fact excites the mental affection called the 
emotion, and that this latter state of mind gives rise to the 
bodily expression. My theory, on the contrary, is that the 
bodily changes follow directly the perception of the exciting fact, 
and that our feeling of the changes as they occur is the emotion. 
Common sense says, we lose our fortune, are sorry and weep; 
we meet a bear, are frightened and run; we are insulted by a 
rival, are angry and strike. The hypothesis here to be de- 
fended says that this order of sequence is incorrect, that 
the one mental state is not immediately induced by the 
other, that the bodily manifestations must first be interposed 
between, and that the more rational statement is that we feel 
sorry because we cry, angry because we strike, afraid because 

377 



378 PSYCHOLOGY 

we tremble, and not that we cry, strike, or tremble, because 
we are sorry, angry, or fearful, as the case may be. Without 
the bodily states following on the perception, the latter would 
be purely cognitive in form, pale, colorless, destitute of 
emotional warmth. We might then see the bear, and judge 
it best to run, receive the insult, and deem it right to strike, 
but we should not actually feel afraid or angry. . . . No 
reader will be inclined to doubt the fact that objects do excite 
bodily changes by a preorganized mechanism, or the further 
fact that the changes are so indefinitely numerous and subtle 
that the entire organism may be called a sounding-board, which 
every change of consciousness, however sHght, may make 
reverberate. . . . Every one of the bodily changes, whatever 
it be, is felt acutely or obscurely, the moment it occurs."^ 

This statement makes emotion a group of organic sensa- 
tions reiiexly excited by the emotional object or situation. 
No place is given in the theory to the various shadings and 
combinations of the affections of pleasantness and unpleasant- 
ness which enter into and give affective character to the feel- 
ings. The theory also denies the very widely accepted belief 
that the primary central excitation reaching the brain from 
external objects or events is the basis of emotion. Neither 
the perception nor the ideation of an emotional object or event 
is in itself able to arouse an emotion. Not until the secon- 
dary stimulation or organic back-flow reaches the central brain 
areas does the emotion arise. The theory, therefore, calls 
attention in a unique way to two very important facts which 
have been neglected by the common-sense view of the emo- 
tions. In the first place, we must agree that exciting facts 
and situations (emotional stimuli) do set up instinctive re- 
flexes in the vital organs and in the muscles of the body. 
The sight of a wild beast causes us to start and tremble 
before we have had time to image the danger. The shortened 
breath, the pallid face, and the "heart jumps" are immediate 
instinctive reflexes which precede the feeling of terror which 

^ "Principles of Psychology," II, pp. 449-451. 



EMOTIONS 379 

seizes us. The proffered insult immediately closes our 
fists and sets our teeth. The piece of bad news reflexly 
causes the lachrymal effusion. The embarrassing situation 
causes the reflex of swallowing, of clearing the throat, or 
of incipient coughing. As James says: "Emotional objects 
are certainly the primitive arousers of instinctive reflex 
movements." In the second place, we do sense these bodily 
reverberations as organic and kinaesthetic sensations, some- 
times acutely and sometimes obscurely, during the course 
of the emotion. We, therefore, agree that these bodily 
reverberations are important elements in the make-up of 
the emotional seizure. We hold, however, that the theory is 
illogical in that it takes a part for the whole. Can we agree 
to the statement that the complex of organic and kinaesthetic 
sensations is the emotion ? 

James proposes two lines of argument in support of his 
theory. The first one is as follows: "//," he says, ^^ we fancy 
some strong emotion, and then try to abstract from our con- 
sciousness of it all the feelings of the bodily symptoms, we find 
we have nothing left behind, no 'mind-stuff' out of which the 
emotion can be constituted, and that a cold and neutral state 
of intellectual perception is all that remains. . . . What 
kind of an emotion of fear would be left if the feeling neither 
of quickened heart-beats nor of shallow breathing, neither 
of trembling lips nor of weakened limbs, neither of goose- 
flesh nor of visceral stirrings, were present, it would be quite 
impossible for me to think. Can one fancy the state of rage 
and picture no ebullition in the chest, no flushing of the face, 
no dilatation of the nostrils, no clenching of the teeth, no im- 
pulse to vigorous action, but in their stead limp muscles, calm 
breathing, and a placid face?"^ James asserts that he can 
imagine no such condition— that without the first set of bodily 
excitations "the rage is as completely evaporated as the sen- 
sations of its so-called manifestations" and that the only 
thing that can take its place is a cold-blooded cognitive con- 

* "Principles of Psychology," II, pp. 451-452. 



380 PSYCHOLOGY 

sciousness. He goes on to say: "A purely disembodied 
human emotion is a nonentity. I do not say that it is a 
contradiction in the nature of things, or that pure spirits are 
necessarily condemned to cold intellectual lives; but I say 
that for us, emotion dissociated from all bodily feeling is 
inconceivable." Critics have already pointed out the illogical 
nature of this argument. The bodily organic sensations 
might well form an important or necessary part in emo- 
tion and yet not be the emotion. It may be impossible 
for emotion to exist without the organic reverberations, but 
it does not follow that these reverberations constitute the 
whole emotion. 

The second line of argument is based upon certain patho- 
logical cases found in insane asylums in which emotion is 
objectless — i. e., cases where persons are seized by morbid fear 
or other emotion without cause. Either during or after the 
attacks the patients are unable to give any reason for the 
emotion. They are simply seized at times by uncontrollable 
fits of fear. Other unmotived emotions — ^anger, melancholy — 
may also manifest themselves and persist without cause. 
If,, according to James, the patient is unable on account of 
some pathological nerve condition to take a full breath, has 
fluttering of the heart and visceral disturbances, and mani- 
fests an irresistible tendency to take a crouching position, 
the combination of the resulting organic sensations makes 
up the emotion of morbid fear. Assuming that in such cases 
the experience is a true emotion, there may be ways of explain- 
ing it without taking it for granted that the combined group 
of organic sensations is the emotion. First of all, the patient 
in his previous experience may have had "fear thoughts," 
or real or hallucinatory presentations of threatening things. 
Since the organic sensations mentioned would be on these 
occasions a part of the emotion, an associative connection 
would be set up between the organic sensations and the real 
or imagined fear presentations. We can readily understand, 
then, how the recurrence of this set of organic sensations can 



EMOTIONS 381 

awaken the associative connections and make active the 
predisposition to the same emotional consciousness. The 
organic factor need not awaken the former presentations 
completely. These presentations may not rise to full con- 
sciousness at all, but remain in the background as vague 
forebodings, or indefinite and shadowy forms of threatening 
things which remain hidden from the patients' introspection. 
Or, the organic sensations may be supplemented by meaning. 
In the past experience of the patient, they may have come to 
stand for fearful things in general. Again, we may of course 
refuse to accept the assumption that the pathological un- 
motived fear is the same as the real emotion of fear. It may 
be only a remnant of the real emotion. These cases, there- 
fore, fail to furnish proof that the organic sensations are in 
themselves the emotion. 

On the other hand, attempts have been made through ex- 
periments upon lower animals to show that the organic sensa- 
tions are not necessary to emotions. Sherrington, for in- 
stance, by severing certain nerves in dogs, cut off all sensa- 
tions coming from the viscera, skin, and muscles behind the 
shoulder. These animals showed no loss of emotions after 
the operation, so far as could be observed. This, however, is 
not conclusive. In the first place, we know very little about 
the "inner" consciousness of animals. We can only observe 
their outer behavior. Who can tell whether the dog's affec- 
tive experiences were the, same after the loss of the organic 
sensations? The outward behavior and organic responses 
may have manifested no observable difference, but we must 
remember that these responses are reflex movements and 
might very well take place, even though their resulting sen- 
sations were not aroused in the animal's consciousness. In 
the second place, even if we agree that the emotions are pres- 
ent after the elimination of the organic sensations, the images 
or "memory" of these sensations may still be aroused by 
virtue of the associative connections formed in previous 
experiences. 



382 PSYCHOLOQY 

Another objection to the theory has been offered by its 
opponents. The objection is founded upon the fact that 
different emotions may manifest the same bodily expressions. 
Thus we may cry in extreme joy as well as in sorrow, or 
tremble in anger as well as in fear. If, say the critics, the 
emotion is the report in consciousness of bodily expressions, 
then the quality of emotions must be determined by the 
character of the expressions. How, then, can the same ex- 
pression be experienced in such different ways? Also, it is 
urged, the same emotion may manifest on different occasions 
very different bodily expressions. Thus at one time in fear 
we may crouch and hide while at another we may run away. 
How, then, can these quite different bodily expressions be 
experienced in the same way? In reply to these objections 
it may be said that a single expression does not determine 
the character of the emotion. It is rather determined by a 
complex of bodily expressions. Crying in sorrow is not its 
only, or even its fundamental expression. Other more deeply 
seated organic reactions give it its character. Surely there 
may be certain variations in the expressions of an emotion 
without destroying its general character. Unhappily no one 
has yet determined the exact character of the bodily expres- 
sions in emotion, or made out any uniform correlation between 
the emotions and their expressions. Shepard, who has made 
a very careful study of the changes in circulation and breath- 
ing during affective conscious states, concludes that no classi- 
fication of the feelings can be made on the basis of their bodily 
expressions.^ We cannot, therefore, be dogmatic. We must 
wait for further evidence. 

It is a commonly accepted hypothesis, and the facts so 
far as we know them indicate that affection arises from cen- 
tral brain processes which also give rise to experiences of sen- 
sory or ideational character.- Visual, auditory, gustatory, 

^ American Journal of Psychology, 1906, XVII, p. 522. 

^ There are some divergent views, however. Miinsterberg, for instance, 
considers that the affective states of pleasantness and unpleasantness are the 



EMOTIONS 383 

and olfactory stimuli, as well as organic and kinaesthetic 
stimuli arouse affective consciousness. If this is true, and if 
emotions are complexes of cognitive and affective conscious- 
ness, then not only do organic and kinaesthetic sensations 
contribute to their make-up, but all the other forms of con- 
sciousness contribute their part, too. There is no reason to 
suppose that the organic sensations alone have the power to 
arouse emotional experiences. 

It may be that the back-flow of organic sensations is a 
very important factor in emotions, or even that its presence 
makes the difference between the stronger emotions and the 
simpler and calmer feelings. The agitating nature of emo- 
tion is due, without doubt, to the presence of organic dis- 
turbances. But in both cases (that of simple feelings and of 
the stronger emotion) the manner in which the sensory or 
cognitive stimuli enter and affect the central areas gives rise 
to the distinctive affective components in the emotion. 

The chief difference, therefore, between the theory as 
originally outlined by James and the theory which is sup- 
ported here lies in the number and kinds of cognitive states 
admitted into the emotion; and in the value placed upon the 
affective elements as component parts of the emotion. James 
limits the emotion to the consciousness of the organic dis- 
turbance, or bodily resonance, set up reflexly by the emo- 
tional stimulus. We believe, on the other hand, that the 
perception of an emotional object or event and the ideational 
processes which are awakened by the perception as well as 
the mass of organic sensations aroused by the bodily reflexes 



mental correlates of nerve-currents which reflexly excite muscular movements 
of extension and contraction. If the movements are not reflexly excited they 
are reported in consciousness as kinaesthetic or muscular sensations, but if 
they are reflexly excited they appear as affection. This would appear to fur- 
nish a basis for the James-Lange theory. Organic disturbances set up through 
reflex and instinctive pathways would be reported back to consciousness as 
an emotional complex. There is no evidence, however, that James had any 
such hypothesis in mind. On the other hand, he considered the organic 
rebound as a sensory process. 



384 PSYCHOLOGY 

enter into the emotional complex. In addition, we believe 
that the various affective accompaniments of these cognitive 
factors also help- to determine the character of the emotion. 
All these components form a synthetic unity, which we call 
emotion. 

It is fair to say that James has modified the original 
statement of his theory somewhat. This modification con- 
sists in the first place in the admission of the affective nature 
of the perception which starts an emotion. Either pleasant- 
ness or unpleasantness, he admits, may inhere in the sensa- 
tions and be fused into the perception into which they are 
combined. In the second place, he has amplified his first 
statements by explaining that it is not the perception of the 
simple object alone that initiates emotion, but the perception 
of a total situation of which the object is a part. The object 
may in time, after we are familiar with its context, become 
capable of suggesting the total situation and the suggestion 
may start the emotion. 

The Instinctive Reactions and Emotions. — If we consider 
a list of the most important instincts we shall find that they 
all manifest an emotional aspect. For instance, fear is both 
an instinct and an emotion — an instinct in so far as it is a 
tendency leading to native forms of motor reactions, such 
as flight, crouching, or hiding — an emotion in so far as it is 
a feeling. Pugnacity and anger, curiosity and wonder, paren- 
tal instinct and tender emotion are other pairs of terms, the 
first of which stands for an instinct and the second an emo- 
tion. Instinctive situations tend to set up emotions as well 
as instincts. On the other hand, emotional stimuli tend to 
arouse instinctive reactions. The instincts which are strongly 
marked by an emotional counterpart, like those of anger 
and fear, manifest, in addition to their outward acts, motor 
reactions which affect the inner organic processes. The in- 
stincts which are less marked by emotional tone, like those 
of play and imitation, manifest little or no tendency to dis- 
turb the inner organic processes. All of their energy is con- 



EMOTIONS 385 

sumed in acts which affect outer objects. In so far, then, as 
an instinct initiates motor impulses which affect primarih' 
the organism, it gives rise to emotion, but in so far as it con- 
sists in acts which change the environment or in acts which 
adjust the organism properly to the environment, we think 
of it only as an instinct. 

If we ask why certain instinctive impulses are thrown 
back into organic channels instead of into the more evident 
environmental adjusting mechanism of the body, we may 
find an answer in certain biological theories. The student 
must judge for himself the value of these theories. Why, for 
instance, does the mouth become dry and the skin moist with 
perspiration in fear? Why do we tremble when confronted 
with a fearful object ? The answer which has been commonly 
given in explanation will be more evident if we consider some 
of the other instinctive reflexes found in fear. For instance, 
we start and crouch and shrink into ourselves when fright- 
ened. The movements are the initial stages of running or 
jumping away, and of hiding from the threatening object. 
The movements of running away and hiding have been very 
useful to the organism in just such circumstances. There- 
fore, the starting and crouching and shrinking in fear are 
supposed to be weakened repetitions of useful acts. Accord- 
ingly, all emotional reactions which are not now plainly use- 
ful are looked upon as organic survivals of acts that were 
once useful and adaptive reactions in racial development. 
They are reminiscent of past struggles for existence. The 
disturbances in heart and lung action which are present in 
fear are repetitions of the quickened heart-beat and breath- 
ing needed in flight or combat. "Fear," says Spencer, 
"when strong, expresses itself in cries, in efforts to escape, 
in palpitations, in tremblings; and these are just the mani- 
festations that go along with an actual suffering of the evil 
feared. The destructive passion is shown in a general ten- 
sion of the muscular system, in gnashing of teeth and pro- 
trusion of the daws, in dilated eyes and nostrils, in growls; 



386 PSYCHOLOGY 

and these are weaker forms of the actions that accompany 
the killing of prey." Distention of the nostrils in anger, 
Spencer thinks, is a survival of the manner in which our 
ancestors had to breathe during combat. Many emotional 
expressions have been traced back to early utilitarian adap- 
tations. Trembling in fear may have been an instinctive 
movement preparatory to actual flight. The quickened 
breath of anger harks back to the times of hand-to-hand con- 
flicts with an enemy. Clenching the teeth and opening the 
lips, which is now often observed in angry men, is a survival 
of those early struggles in which the teeth were used for 
attack. Opening the mouth in astonishment was useful in 
that it aided in attentive listening. Blushing of the face and 
neck, according to Wundt, serves the purpose of relieving 
the brain of blood-pressure, which is increased during certain 
emotional excitement. Many more illustrations of emotional 
reactions that were once clearly serviceable may be found. 
Man has advanced beyond the stage where many of the 
originally serviceable reactions are of present utility. They 
are, therefore, not executed as they once Were. Modified, 
or atrophied, they now exist only in weakened and rudimen- 
tary form as tendencies to action, and they fail to do more 
than stir up the organism. In some cases they are antago- 
nistic to later-acquired co-ordinations, and are consequently 
partially inhibited or suppressed. 

While it seems probable that certain emotional reactions 
can be explained by the principle of utility, there are others 
which refuse to be accounted for in this way. In what way 
can the cold sweat, nausea, and dryness of the mouth in fear, 
the lump in the throat in grief, and the swallowing in embar- 
rassment, together with many other organic excitements, be 
thought of as derived from once-useful adjustments? James 
is of the opinion that many of the emotional reactions are 
"purely mechanical or physiological outpourings through the 
easiest drainage-channels," and are to be looked upon as 
accidental or even pathological disturbances rather than once- 



EMOTIONS 387 

serviceable reactions. Mosso, who has given the subject 
much attention, also thinks that many emotional organic 
disturbances are morbid and useless reactions. He says: 
"We have seen that the graver the peril becomes, the more 
do the reactions which are positively harmful to the animal 
prevail in number and in efficacy. . . . Their extreme degree 
is indicated by morbid phenomena which show an imperfec- 
tion in the organism. We might almost say that Nature had 
not been able to frame a substance which should be excitable 
enough to compose the brain and spinal marrow, and yet 
which should not be so excited by exceptional stimulation as 
to overstep in its reactions those physiological bounds which 
are useful to the conservation of the creature." ^ 

Recent physiological researches have, however, shown 
that some of these emotional organic disturbances in ques- 
tion do serve the organism in emotional crises. It has been 
shown, for instance, that when a cat is frightened or angered 
by the barking of a dog certain glands attached to the kid- 
neys immediately begin to secrete a substance known as 
adrenalin. The adrenalin is thrown into the blood and 
causes the blood vessels in the abdominal organs to contract 
and those in the legs, lungs, heart, and brain to dilate. The 
blood is thus forced into the muscles which are needed for 
escape or attack, and the heart, lungs, and brain are prepared 
for the extraordinary effort needed to adjust the animal to 
the new situation. The barking of the dog awakens in the 
cat impulses of attack or flight, which in turn stimulate the 
action of the adrenal gland. The emotional seizure thus 
serves a definite purpose. Other emotions may have similar 
stimulating effects on the different glands of the body by 
virtue of which the organism is better prepared for needed 
adjustments. 

According to Darwin all emotional reactions, or expres- 
sions, are due either (i) to survivals of once-useful acts, or 
(2) to movements antithetic to those acts, or (3) to move- 
^ "La Paura," Appendice, p. 295. 



388 PSYCHOLOGY 

ments resulting from excess nervous discharge or overflow. 
The first principle we have discussed. The principle of anti- 
thetic movement is stated by Darwin as follows: Certain 
mental states lead to certain forms of actions which are of 
service to the organism. When a directly opposite state is 
induced there is a strong involuntary tendency to the per- 
formance of movements of a directly opposite nature, al- 
though they are of no use. In some cases these movements 
are highly expressive.^ Darwin explains the expressions of 
the feeling of impotence by this principle. The feehng of 
power which is present in the emotion of rage leads to the 
expression of lowered eyebrows, raised shoulders, and clenched 
fists. Now the feeling of impotence is a mental state di- 
rectly opposed to the feeling of power. Accordingly, it mani- 
fests a tendency to movements of an opposite nature, which 
are raised eyebrows, lowered shoulders, and open palms. 
This principle of antithesis has not been very widely accepted 
by critics. The third principle — that of excess nervous dis- 
charge or overflow — we have accepted as the neural condition 
accompanying the impeded conscious activities which form 
the psychical basis of emotion. 

In emotions, then, we are aware more or less vaguely of 
a mass of organic reactions and bodily movements. Instead 
of our having an emotion first and acquiring its so-called ex- 
pressions later, it turns out that certain useful instinctive 
reactions acquired in the struggle for existence, and certain 
movements due simply to excess nervous discharge have left 
after-effects within us which are conditioning factors in emo- 
tional seizures. It is, therefore, not correct to think of these 
bodily reactions merely as expressions of emotions. Their 
function was not to express emotions, but rather to respond 
in an adaptive way to the situations which start the bodily 
reactions. To an external observer these reactions may be 
signs of the presence of certain emotions, but from the point 

1 Taken with verbal changes from "The Expressions of Emotions in Man 
and Animals," 



EMOTIONS 389 

of view of the person who is experiencing the emotion they 
are not expressions. Whenever we speak of these reactions 
as expressions of emotions we mean only that they are symp- 
tomatic of emotional states. 

Among the bodily reactions characteristic of emotion are 
the facial expressions which seem to form a class by them- 
selves. Thus, we look disappointed, hurt, or pleased; we 
smile, shed tears, or turn up the nose. These so-called emo- 
tional expressions call for consideration because they do not 
at first glance seem to come under the principle of utility. 
Of what use to the organism was the reaction of smiling, or 
shedding tears? Thorndike^ asserts that they are useful re- 
actions in that they make a difference in the behavior of other 
men toward us. Any woman knows the utility of tears in 
this respect, and has instinctively made effective use of them 
from the very beginning. Wundt^ proposes another explana- 
tion. He thinks that the facial expressions of emotions cor- 
respond to definite reflex and adaptive adjustments made in 
response to stimuli affecting the facial sense-organs, especially 
those of taste and smell. Thus the emotional expressions of 
the mouth resemble the reflexes set up by the taste-stimuli 
of sour, bitter, and sweet. When a man looks "sour" or 
"bitter" in disappointment, or anger, his mouth makes the 
same movements and assumes the same positions that it 
does in actually tasting sour and bitter substances. "Sour 
and bitter looks depend upon reflex movements which serve 
to prevent the contact of certain ill-tasting substances with 
the portions of the tongue most sensitive to them." Like- 
wise when the maiden looks sweet and smiling the facial ex- 
pression is similar to that in actually tasting a sweet sub- 
stance. Since the tip of the tongue is most sensitive to 
sweet, the movements consist in drawing back the lips about 
the tip of the tongue in order to bring it "in as complete 
contact as possible with the sweet substance." 

1 "Educational Psychology," vol. I, p. 158. 

- "Human and Animal Psychology," Lecture XXVI. 



39° PSYCHOLOGY 

Now, the taste of sour and bitter and sweet are connected 
with the affective states of pleasantness and unpleasantness. 
It seems probable that other cognitive experiences having 
similar affective states should become associated with these 
facial senses, especially in the primitive stages of life. Un- 
pleasant experiences of any kind would naturally remind 
primitive man of these gustatory sensations connected with 
food-getting, and their arousal would initiate their motor 
reflexes and so give rise to sour and bitter looks. Likewise 
pleasant experiences would make him look sweet and smiling. 
In time the gustatory terms would drop out so that the con- 
nection between unpleasant experiences and sour and bitter 
looks and between pleasant experiences and sweet looks 
would become a direct one. If this is true it seems necessary 
to assume a neural connection in the central nervous system 
between other centres than the gustatory centre and the 
muscles of facial expression. Observation of the facial con- 
tortions of any new-born baby seems to lend support to this 
hypothesis. 

The result is that "analogous feelings" tend to copy or 
imitate already established responses to stimuli. This prin- 
ciple explains why in moral disgust we raise the nostrils and 
turn the head away, just as we do when actually experienc- 
ing a nauseous odor. We must, of course, allow for a cer- 
tain amount of variation and modification in these mimetic 
movements. They may become, as emotional expressions, 
more or less modified or changed from their original form. 
It is interesting to note that these borrowed reactions now 
seem perfectly appropriate to the emotions in which they 
appear. 

The fact that mimetic movements are present in the new- 
born child raises a question in heredity and evolution. This 
explanation of emotional facial expressions seems a plausible 
one for the individual, but if the expressions are original in 
the new-born child the associative connections formed in 
primitive experiences must have been fixed in heredity. Since 



EMOTIONS 391 

the associations themselves cannot be transmitted from one 
generation to another, the neural mechanism of the associa- 
tion must be. If the young child, long before he has had 
any extended experience in gustatory sensations, manifests 
the emotional facial expressions during his affective states, 
then he must have inherited the neural connections whereby 
central stimulation, as well as gustatory stimulation, can 
occasion the mimetic responses. We cannot go further into 
this question here because it involves certain fundamental 
biological problems concerning heredity which have not yet 
been settled. 

Conditions Which Give Rise to Emotions. — Since emo- 
tions are characterized by the bodily resonance resulting from 
instinctive impulses which exhaust themselves within- the 
organism itself, our next task will be to find out under just 
what conditions these bodily affecting reflexes are called into 
being. Why do certain objects or events excite the bodily 
affecting impulses instead of the motor co-ordinations which 
deal directly and efficiently with external objects ? We shall 
find in examining a series of typical emotions that they are 
initiated by the perception or ideation of objects or events 
which obstruct our conscious plans and purposes, and inhibit 
the adaptive voluntary and involuntary co-ordinations which 
serve to carry them out. Zeno the Stoic said that "emo- 
tion is a movement in opposition to the soul." In all emo- 
tional seizures there is a sudden interruption of conscious 
action and a consequent checking of voluntary control be- 
cause of the presentation of certain stimuli to which the 
organism does not consciously adjust itself. In all cases of 
blocked conscious control there are two possible results. 
Either the nervous excitation, set up in the brain centres by 
the stimuli, may drain off into co-ordinated and smoothly 
running instincts and habits which are effective in dealing 
with the situation, or it may be turned back and diffused 
into organic and motor channels and there arouse a mass of 
conflicting organic and motor impulses. It is the latter 



392 PSYCHOLOGY 

alternative which furnishes the condition for emotion. We 
have already noted that in such cases part of the nervous 
overflow follows old hereditary pathways leading to once use- 
ful reflexes. It is also true that part of the nervous excita- 
tion may escape into ineffective habitual and voluntary 
pathways, i. e., ineffective so far as the present stimulus is 
concerned. The essential condition for emotion, however, is 
that conflicting motor tendencies are aroused, and that these 
tendencies are initiated by the appearance of conscious states 
which suddenly block conscious activity and interrupt the 
continuity of our plans and purposes. In so far as con- 
sciously directed activity or instinctive behavior does not 
lead to conflicting impulses, but runs out into single and 
consistent lines of adaptive movements, the condition for 
emotion is not present. We may see this principle illustrated 
in any one of the clear-cut emotions. For example, a trav- 
eller in the north woods becomes aware that a pack of hun- 
gry wolves is close upon his heels. The perception of this 
fact suddenly breaks in upon his consciousness and intrudes 
itself as a barrier to the purposes dominating his mind at the 
time. He sees himself torn to pieces by the hungry beasts, 
and all his plans frustrated. His mental faculties are para- 
lyzed. He cannot think himself out of the difficulty. The 
nervous excitement started by the sound of the oncoming 
pack is discharging into organic and motor pathways. He 
turns pale, trembles, and feels a sickening sensation in his 
stomach. His mouth becomes dry and beads of perspiration 
stand out on his forehead. He is torn by conflicting im- 
pulses to cry out, to run, to hide, to stand still, to crouch 
down, to defend himself, etc. Just as long as our traveller 
is unable to shut out the disturbing and interrupting con- 
scious states which are initiated by the threatening stimulus, 
and fails, therefore, to get control of consciousness, he is 
swept by paroxysms of fear. On the other hand, the mo- 
ment he is able to think of some way out of his dilemma — if 
he happens to remember that on the trail just ahead, under 



EMOTIONS 393 

a clump of trees, is a log cabin which will furnish a means 
of escape from danger, the obstructing conscious states are 
crowded out. The onward flow of his mental processes will 
be resumed and all his nervous energy will drain off into the 
single adaptive reaction of running. So long as no doubt of 
his ability to reach the cabin in time enters his mind there 
will be no conflicting impulses within and the emotion will 
die down. In this case, the perception of the wolves is not 
an obstruction to the conscious purposes which the traveller 
has in view. The perception of the wolves takes its place in 
his consciousness without interrupting its progress toward 
the desired end. The chances are, however, that the trav- 
eller will be unable to keep his thoughts fixed upon the sijigle 
purpose and the movements necessary to carry it out. Each 
fresh outburst of the howling beasts behind will tend to dis- 
tract his mind and set up conflicting impulses to look back 
to see if the pursuing animals are gaining upon him, to stop 
and defend himself, to hide, or climb a tree. The organic 
overflow of nervous excitement again takes place and recur- 
rent waves of fear seize him. Not until the antagonism of 
mental states and the conflict and inhibition of impulses has 
ceased will he be freed from his terror.^ 

The emotion of joy manifests entirely different sets of 
antagonistic conscious states and conflicting impulses, but 
the same conditions of obstructed conscious flow and conse- 
quent diffusion of nervous excitation are found here as in 
other emotions. The telegram announcing the final success 
of some enterprise for which we have been eagerly striving 
suddenly puts a barrier across the line of our thoughts. For 
the moment we are dazed. The mental processes do not go 
on in the same uninterrupted way. We cannot instantly 
adjust ourselves to the new situation. We are seized with 
impulses to jump and dance, to shout, and laugh, to thump 
or hug the person nearest at hand, or even to cry with tears 
of joy. Previous thoughts of doubt and failure are revived 
' See also Angell's description of fear, "Psychology," p. 375. 



394 PSYCHOLOGY 

and overcome by the present knowledge of success. The 
emotion rises in proportion as we become aware of the ten- 
sion and stress between the impulses coming from the antago- 
nistic and oscillating thoughts. Not until the mental cyclone 
has passed do we get possession of our senses and act in a 
sane and sensible manner. And so we might go through the 
list of emotions only to find in each case the same condition 
of conscious interruption and conflict. Some emotions mani- 
fest this condition more markedly than others. As it mani- 
fests itself less and less the emotions shade off into simple 
feelings. 

The different qualities which emotions show are deter- 
mined by the nature of the organic and muscular responses 
aroused by the various emotional objects and events. We 
have already found that many of these different organic re- 
sponses are in turn determined by hereditary influences which 
reach far back in organic development. They are the rem- 
nants of adaptive reactions which now play upon the organ- 
ism and re-echo earlier struggles for existence. But we must 
not forget that these reactions are set off by the overflow and 
diffusion of nervous excitement accompanying interrupted or 
blocked conscious processes. 

Significance of Emotions. — ^Emotional seizures appear in 
situations where new adjustments of consciousness are needed 
in order to go forward efficiently. They are signs that the 
organism has need of more than the usual supply of nervous 
energy to meet the situation presented. The temporary agi- 
tation and bodily disturbance may therefore be looked upon 
as a means of preparing the organism for extraordinary 
effort. The diffused excitement starts the machinery going 
along many lines of bodily activities, and thus serves as a 
kind of general preparation. It may seem at first thought 
that we shall have difficulty in applying this principle to the 
depressing effect of an emotion like that of grief. But we 
must remember that situations which occasion the depress- 
ing emotions do not call for vigorous action to meet them 



EMOTIONS 395 

properly. On the other hand, they demand quiet and repose 
before we can become adjusted to them. The emotion in 
these cases furnishes an outlet for the excitement caused by 
the disturbing facts. Sorrowful situations are for the most 
part events that have already taken place, and nothing that 
we can do will change them. The situation requires then 
simply a rational and philosophic attitude on our part. 

Classification of the Emotions. — Since emotions are highly 
complex mental states into which many different conscious 
elements may enter, it is to be expected that psychologists 
will group them in all sorts of ways, accordingly as they em- 
phasize this or that factor. Emotions may be classified upon 
the basis of their predominant and primary affective states 
as pleasant and unpleasant emotions; or according to the in- 
tensity of these affective states as weak or strong emotions; 
or according to the character of their bodily reactions as 
sthenic or asthenic emotions; or according to the form of their 
occurrence as slowly arising or suddenly arising emotions; 
or according to the external situations which occasion them 
as food emotions, sex emotions, etc. ; as egoistic or non-egoistic 
emotions; as sensuous or intellectual emotions; as subjective 
or objective emotions, and many more. Some of these classi- 
fications are purely psychological and some psychophysical. 
Wundt has proposed a very elaborate classification based 
upon psychological differences only.^ Bain's classification of 
the emotions found in the Appendix of his "Emotions and 
the Will" is worthy of note. 

Emotions and Memory. — ^We have already spoken of the 
fact that feelings are not likely to be recalled, but are created 
anew when our cognitive experiences are recalled. As we 
should expect, our emotions, too, are not subject to recall. 
We can remember that we were angry or sorrowful, but we 
do not image the emotions themselves. When we think of a 
past insult the anger which arises is a new anger, not the old 
anger that we experienced at the time the actual insult was 

^ "Outlines of Psychology," English translation, p. 198, paragraph 13. 



396 PSYCHOLOGY 

received. The more vividly we image the circumstance the 
more hkely we are to experience anger when thinking about 
it. The thought causes the same impeded consciousness and 
the same or similar organic diffusion and conflicting motor 
impulses and the emotion becomes actual, not recalled. 
Shame and anger are especially liable to be recreated by the 
memory of the original events which occasioned them. We 
blush with shame when thinking of some recent folly of ours. 
We set our teeth in anger when we recall some personal 
affront. 

Time, however, lessens the intensity of these repeated 
emotions, or even leaves us cold and without emotional 
warmth. Events, which at first stir our very being when we 
think of them, come in time to be recalled with no emotion 
whatever, although the events themselves are remembered as 
vividly as before. This means that these memories become 
rationalized and harmonized into our conscious life, so that 
they cease to be obstructing conscious factors. If this were 
not so, we should be so beset by disturbing emotions that 
clear thought and efficient behavior would be impossible. 
The nervous energy which is at first set free in emotional 
excitement becomes available, through this process of accom- 
modation, for rational control. This subduing effect of time 
makes the difference between the hot-headed and impetuous 
youth and the mature and experienced man of the world. 



CHAPTER XVIII 
CONSCIOUSNESS AND BEHAVIOR 

From its very first appearance in the life process, con- 
sciousness has been connected with the motor responses. In 
fact its fundamental function has been to guide behavior. 
But the individual begins his career with a group of native 
reactions which are not consciously controlled or directed. 
These native forms of behavior are the purely physiological 
reactions, the reflexes, and the instincts. They are present 
prior to experience on the part of the individual, and althou'gh 
they are not controlled by him they nevertheless serve to 
adjust him to his first surroundings. These native reactions 
serve as a foundation upon which the individual builds up 
his acquired forms of behavior which are necessary for his 
continued existence. 

The native reflexes and instincts represent the individual's 
hereditary endowment in the way of behavior, while the ac- 
quired reactions represent what he gains for himself through 
the aid of consciousness. After the first stages of develop- 
ment both native and acquired reactions are present. As 
development proceeds the acquired reactions increase in 
number and complexity and the native reactions are modified 
by experience. The behavior of the organism becomes, 
therefore, a varying mixture of native and acquired reactions 
— sometimes largely native, sometimes largely acquired reac- 
tions, depending upon whether the conscious experience of 
the organism plays a small or large part in determining its 
behavior. 

So far we have spoken only of the co-ordinated reactions 
of the organism. Over and above these reactions the organ- 
ism manifests a group of unco-ordinated and diffuse move- 

397 



398 PSYCHOLOGY 

ments which are usually spoken of as random movements. 
While these movements are the result of stimulation, they 
are not directed to any particular end. They are the out- 
come of diffuse nervous energy flowing into the muscles of 
the body. 

To complete our list of bodily reactions, or behavior, we 
must add the important group of volitional reactions. Voli- 
tional reactions are the acts which are immediately deter- 
mined and controlled by consciousness. 

Summing up the forms of behavior we have: 

1. Purely physiological reactions, 

2. Unco-ordinated random reactions. 

3. Native reflexes, 

4. Instincts, 

5. Acquired reflexes. 

6. Habits. 

7. Ideo-motor reactions. 

8. Volitional reactions. 

The physiological reactions are those in which conscious- 
ness plays the least part. They are usually considered as 
unconscious reactions.^ They are the reactions involved in 
respiration, circulation, intestinal processes, glandular secre- 
tions, pupilary reflexes, etc. 

The unco-ordinated random reactions are the diffuse move- 
ments which have no definite end, A brightly colored object 
may stimulate the young infant to make many random move- 
ments in the different parts of the body. Head, face, arms, 
legs, and feet may all move about in an aimless way when 
he catches sight of the object. Since the child has inherited 
no definite, preformed neural pathway for carrying off all 

1 The purely physiological reactions are not absolutely divorced from con- 
sciousness. It is a demonstrated fact that mental states may influence or 
even initiate these physiological activities. The perception of food may start 
the secretion of saliva. The presence in the mind of certain ideas may affect 
circulation and respiration — the bated breath, the blush of shame, the pallor 
of fear, the flush of anger, all testify to the effect of consciousness upon the 
purely physiological activities. 



CONSCIOUSNESS AND BEHAVIOR 399 

nervous excitement, it is diffused into various pathways lead- 
ing to a large number of muscles. This diffused activity has 
been called "excess reaction" or "multiple response to a 
single stimulus." 

The native reflexes are the simplest and most direct co- 
ordinated movements. They are made in response to sensory 
stimuli. The closing of the baby's hand when the palm 
is stimulated and the sucking movements following tactual 
stimulation of his lips are common illustrations of the native 
reflexes. 

The instincts are complex native reactions composed of a 
number of native reflexes chained together in such a way 
that they lead to an adjustment of the organism as a whole 
to some outer situation. Sometimes the term instinct is used 
to signify all the native reactions from the purely physio- 
logical reactions to the most complex native reactions. We 
shall use the term to signify only the complex chained reac- 
tions leading to a single end. Instincts are inherited forms 
of reaction and are, therefore, the result of the transmission 
from parent to offspring of preformed neural pathways. 
While instinct is not consciously controlled by the individ- 
ual, it is nevertheless attended by an impelling consciousness, 
craving or appetent in quality. Illustrations of instincts are 
found in the reactions of fear, anger, jealousy, rivalry, ac- 
quisitiveness, parental love, play, and imitation. In man 
instincts are rarely pure, for they are modified by experience 
and supplemented by volitional and acquired activities. 

The following reactions are all acquired, and differ from 
the preceding forms of motor activity in that they are learned 
during the lifetime of the individual as the result of his own 
experience. 

The acquired reflex is the simplest acquired response. Ac- 
quired reflexes are the elementary reactions out of which 
habits are formed. These reflexes are direct responses to 
sensory stimulation. Illustrations of acquired reflexes are 
found in the simple movements of skill which when chained 



400 PSYCHOLOGY 

together constitute ability in playing tennis, performance on 
the piano, etc. 

Hahit bears very much the same relation to acquired re- 
flexes that instinct bears to the simple native reflexes. Habit 
is a complex act composed of a number of simple reflexes 
chained together and so co-ordinated that they result in 
movements toward a definite end. Habit is like instinct in 
that it is a relatively fixed form of reaction, depending upon 
the existence of neural pathways and going on without the 
control of consciousness. It is unlike instinct in that it is a 
form of behavior which has been learned by the individual, 
acquired by virtue of his own experience. It is individual 
rather than racial in its origin. Movements which are often 
repeated under conscious direction become habits. The piano- 
player at first must consciously direct each single movement 
of his fingers, but after many repetitions the movements be- 
come so closely associated together that they may go on 
without conscious control. According to the "law of habit" 
motor reactions once made make it easier for the same reac- 
tions to occur again. This is due to some form of neural 
modification left in the nerve pathways of the brain by past 
experience. The nervous material is sufficiently plastic to be 
modified by repeated neural activity, and yet sufficiently 
stable to retain the modifications. 

Habit involves the perception, or image, or thought of 
some object or situation which has in the past been associated 
Avith the motor activities making up the habit and, in addi- 
tion, the consciousness of the sensations arising from the 
simple movements as they take place. Each sensation is the 
cue for the next movement, which in turn gives another sen- 
sation, serving in its turn as the cue to another movement, 
and so on until the series of movements and sensations are 
run off. This sensory-motor process takes place within some 
conscious purpose or plan. The plan or purpose does not, 
however, include the conscious control of the single move- 
ments. The part which kinaesthetic sensations play in habit 



CONSCIOUSNESS AND BEHAVIOR 4OI 

is made evident by the fact that if they are absent habit is 
seriously interfered with. For instance, in locomotor ataxia 
the patient is, by reason of a diseased condition of the spinal 
cord, insensible to the sensations of movement in the lower 
extremities. For this reason locomotion becomes very im- 
perfect and in some cases impossible. By means of certain 
drugs sensations of movement in the hand and arm may be 
lessened or abolished for a time. This temporary anaesthesia 
makes it extremely difficult for the hands to perform any of 
their accustomed acts or habits. 

Ideo-motor reactions differ from the reflexes in being a re- 
sponse to an image or thought instead of a response to a 
sense presentation. The image of an act or of the result of 
an act may be followed immediately by the act which takes 
place without conscious intention. The act is then said to 
be ideo-motor. 

Volitional Action. — The discussion of volitional action 
should have introduced the description of all the acquired 
reactions — acquired reflexes, ideo-motor activities, and habit. 
For these are best understood in the light of volitional activi- 
ties. Most of our acquired reactions were originally voli- 
tional reactions. Before they became fixed as habitual forms 
of action they required the constant control of consciousness. 
Volitional action is therefore a transitional stage of activity. 
It is really not acquired action, but action in the stage of 
being acquired. From the point of view of consciousness it 
is the standard form of activity. All acquired forms drop 
away from it as they require less and less consciousness in 
their control. Volitional reaction always involves full con- 
sciousness of the action. We know exactly what we are 
going to do before we act, and what we are doing while the 
act is going on. Every act is imaged before it is performed 
and consciously followed during its performance. In addi- 
tion volitional activities involve the consciousness of the end 
or consequence of the act. 

Still another factor must be considered in volitional activ- 



402 PSYCHOLOGY 

ity/ and that is the consciousness of some purpose which is 
accepted or consented to, and within which the image of the 
act and its immediate consequence He. This is what is 
meant when we say that we act with intention. The inten- 
tion or purpose may include in its simplest form only the 
immediate consequences of the act, or it may include the far- 
reaching consequences of some life plan. For instance, I 
may pick up the pen from my desk simply because I con- 
sciously desire to see if it is broken, or because I wish to 
write my will. However, in a fully conscious or volitional 
act, purpose or intention must be present. The conscious- 
ness which presides over volitional activities is impulsive, as 
in all motor consciousness. But it differs from the vague, 
impulsive consciousness accompanying instinct or habit in 
possessing full awareness of the end, awareness of the move- 
ments necessary to accomplish the end, and the conscious 
approval of the end. The impulse may be described as the 
expectant attitude toward or the anticipation of some definite 
end represented as following certain movements. The idea 
of the movements unblocks the outgoing motor pathways 
leading to the muscles involved in the act. Just how this 
unblocking of motor pathways in the brain is accomplished 
by consciousness we do not know. We do know that thought 
of a movement tends to be followed by the movement, and 
that the thought of an end tends to be followed by the move- 
ments necessary to bring about the end. We shall discuss 
this fact more thoroughly later. 

Our analysis has laid bare three factors in volitional 
action: 

1. Consciousness of the act to be performed. 

2. Consciousness of the end or consequences of the act. 

3. Consciousness of an accepted purpose or intention. 

1 Volitional activity is usually thought of as including any forna of activity 
following conscious intention or purpose, whether the activity itself is immedi- 
ately controlled or not. In this sense habitual activities may be termed voli- 
tional activities. But volitional activity as used here is limited to those activi- 
ties requiring constant conscious control. 



CONSCIOUSNESS AND BEHAVIOR 403 

Consciousness of the act and of its end is present in the 
form of images Just before the act is executed. These images 
may be: (i) Resident images, consisting of the mental images 
of the sensations of movement (kinaesthetic images) needed 
in the act, and (2) remote images, consisting of the mental 
image of the result of the act or the end as accomplished. 
For instance, if I image the sensations in the throat and lips 
which occur in the pronunciation of the word "piper," we 
term the image resident. If, on the other hand, I image the 
effect of the act (in this case the word as it would sound when 
it falls upon the ear) , we term the image remote. 

Now it is true, as some psychologists contend, that acts 
may in our every-day life follow upon either form of imagery 
or, in fact, may follow any mental state whatever, provided 
the act has been in the past associated with it. The mere 
sight of the word "piper" on a printed page may be followed 
directly by the act of its pronunciation without any imagery 
interposed between the perception and the act. The thought 
of musical instruments, the image or perception of a rat, the 
thought of children, or the sound of the word Hamelin may 
be followed immediately by the pronunciation of the word 
"piper." But in any one of these cases the response is not 
a "fully conscious" or "volitional" activity. It is rather a 
form of acquired activity which goes on without conscious 
direction — a conscious reflex or a simple habit — depending 
upon past associations. 

A volitional act may be, and usually is, a new act — a new 
adjustment — or a new combination of old acts. Now a new 
act must be consciously imaged and consciously intended 
before it can be performed. It has no past, and consequently 
there are no associations or tendencies established which will 
call it into being. As volitional action is repeated again and 
again, the controlling consciousness which was present in the 
beginning drops out — first the resident, then the remote 
imagery, and even the intention or purpose, until any con- 
scious state which has been associated with the act is sufficient 



404 PSYCHOLOGY 

to initiate it. It then becomes an acquired activity. This 
means that in many cases the first stages in the formation of 
acquired reactions are voHtional. When consciousness is 
able to take note of the native reactions, and can image the 
sensations involved in them, it has adequate material for voli- 
tional activity. Volitional activity, then, lies between the 
native forms of behavior and the acquired forms — between 
what the organism already has and what it is going to have. 
In this transformation consciousness plays the chief role. 

In order to avoid a possible confusion we should note the 
fact that we may exert a volitional control over activities 
which are in themselves not volitional. For instance, voli- 
tional control makes use of acquired reflexes and habits. 
Evidently we must make a distinction between volitional in 
the larger sense and volitional activity in the stricter sense. 
I may will to write a letter and post it before noon to-day, 
but the actual writing and posting activities are all well- 
formed habits and may need little conscious control, and are, 
therefore, in themselves not volitional acts. Even in the 
stricter sense, volitional activities may include well-formed 
habits within the total activity. While consciousness is busy 
controlling the newer parts of the activity-complex, the habits 
within it run themselves off subconsciously. Much of human 
behavior is mixed, partly new and consciously controlled and 
partly old, and, therefore, needing no control. The higher 
and newer forms of behavior are constantly incorporating 
and making use of the lower and familiar forms. 

While this, briefly, is the history of the formation of 
many of our acquired reactions, it is not the only way that 
they are developed.^ So far we have considered only those 
reactions which can be consciously represented before they 
are executed, and consequently we have noted only those ac- 
quired reactions which come to be what they are through di- 
rect conscious control. This conscious control of movement 
is the highest and most direct method of learning new activi- 
*Hobhouse: "Mind in Evolution," chap. VIII. 



CONSCIOUSNESS AND BEHAVIOR 405 

ties. It is probably not present in the lower animals, for it is 
possible only where conscious representation of past move- 
ments and their results exists. While man takes advantage 
of this higher type of learning, he exhibits in common with 
the animals a lower and more primitive method of building 
up his acquired adaptive responses^ — the method of ''trial- 
and-error" or the "hit-and-miss" tj^pe of learning. 

As an illustration of the " trial-and-error " method we may 
describe briefly one of Thorndike's experiments with cats. 
He prepared a box whose cover and front side had been 
replaced by bars an inch apart. A door was placed in the 
front, and so arranged that it would open when a wooden 
button inside was turned from a vertical to a horizontal posi- 
tion. A very hungry cat was placed inside and a bit of fish 
just outside. The stimulus offered by the odor of the fish 
excited the cat to make many random reflex and instinctive 
movements. It ran about clawing and biting at the bars 
until, after a long time, one of the random movements hap- 
pened to turn the button, the door fell open, and the cat 
obtained the fish. When the experience had been repeated 
again and again on succeeding days the cat came gradually 
to omit all the random movements but those of clawing and 
biting the button. After many trials it learned, therefore, 
to open the box immediately by pushing the button with its 
claws or nose.^ In short, it had acquired a co-ordinated re- 
action on the basis of its native activity. There was at first 
a mass of diffused random and instinctive movements called 
out by the stimulus. Then followed the gradual elimination 
of useless and unsuccessful movements, and the selection of 
the movements necessary to meet the situation. There was 
no conscious representation of past experience, and conse- 
quently no conscious control or volitional activity. The first 
successful movement was a chance reaction present in the 
many diffused reactions. The final acquirement of the re- 

^ Ruger: "Archives of Psychology," June, 1910. 
*Thorndik.e: "Animal I atelligence." 



4o6 PSYCHOLOGY 

sponse came only after many repetitions of the same experi- 
ences. Of all the movements which the cat made, the move- 
ment of pushing the button was the only one which was fol- 
lowed by a definite result giving satisfaction. The movement 
thus gradually became associated with the box, button, and 
fish situation. It was subsequently always called out by 
that situation. If, however, in such cases some element in 
the situation is changed, say a shding bolt is exchanged for 
the button, the animal finds itself helpless, and must go 
again through the long process of "trial and error" in order 
to adjust itself to the new condition. The part which con- 
sciousness plays in this process is not as clear as in the case 
of voHtional activity. The feelings of discomfort before the 
proper adjustment happens to be hit upon, and the feeling of 
satisfaction when it is found, form a conscious background 
for the right movements and serve to emphasize and differ- 
entiate them. Here we must assume a native tendency in 
the organism to avoid reactions which bring discomfort and 
seek those which bring satisfaction. 

Young children manifest very markedly this type of learn- 
ing new adaptive responses. Any novel stimulus will call 
out a mass of diffused activity containing some movements 
more or less adaptive. The selection of the right movement 
goes on in much the same way as in the case of animal learn- 
ing. The selection may be characterized as the "survival of 
the fittest responses."^ In adults the method of "trial and 
error" is especially evident in acquiring acts of skill. It is 
present in the first reactions to especially novel situations. 
But, after the first successful response, conscious representa- 
tion and control appears and shortens the process. In the 
acquisition of skilled movements, however, it often happens 
that the finer adjustments are incapable of being analyzed 
out of the total activity. The kinassthetic sensations which 
these movements arouse are too indistinct to be differentiated 
from each other, and so they form a general mass of sensa- 
^ Dexter, Educational Review, vol. XXXIII, p. 8i, 



CONSCIOUSNESS AND BEHAVIOR 407 

tions. In this case the movements cannot be imaged, and 
therefore cannot be consciously controlled. The only method 
by which they can be acquired, then, is that of the "hit-and- 
miss " type — try-try-again method. Continuous and patient 
practice will give variations in the nature of the movements. 
Some of the movements will fail, and some of them will just 
hit the mark and will be accompanied by the feeling of satis- 
faction. Gradually and slowly these latter movements are 
"stamped in" and all others eliminated until the skilled act 
is acquired. The finer adjustments necessary in playing ten- 
nis, billiards, golf, etc., the skilled touch on the piano or vio- 
lin, and the exact tension of the vocal chords in singing, must 
all be acquired slowly by the hit-and-miss method of learn- 
ing. This is so because we are unable to analyze out, and 
consciously represent, the extremely fine adjustments neces- 
sary for these activities. In just so far, however, as we are 
able to sense the fine differences in the kinaesthetic sensations 
of skilled movements, and are, therefore, able to represent 
mentally the movements, we can consciously control them; 
but when the differences are too fine to be sensed we are 
forced to rely on the more primitive method of learning. 

Comparing these two types of learning new adaptive 
responses, we find that the chief difference between them lies 
in the method employed in selecting the responses that are 
to become fixed as the future equipment of the organism. 
The stages of development are as follows: 

Learning through trial and error : Learning through conscious repre- 
sentation : 

1. Native reactions. Native reactions. 

2. Gradual acquirement of sue- Volitional reaction. 

cessful reaction. 

3. Acquired reaction. Acquired reaction. 

In the method of trial and error the second stage appears 
to be a form of natural selection in which the units of selec- 
tion are single reactions within the organism instead of indi- 



408 PSYCHOLOGY 

vidual organisms, as in natural selection proper. The diffused 
random actions furnish variations from which selection of 
the fit reaction is made. According to the theory of natural 
selection, however, no account is taken of the positive agency 
of consciousness in determining what organisms are to be 
selected. The unfit are damped out by the environment; the 
fit survive. On the other hand, in learning new responses, 
even by the trial-and-error method, the organism is undoubt- 
edly aided by consciousness. There is a general conscious 
tendency toward some end. This tendency drives the organ- 
ism to further endeavor. The feelings of pleasure accom- 
panying success and of displeasure attendant upon failure 
serve, as we have already indicated, to stamp in the success- 
ful reaction. 

In the higher type of learning new responses (learning 
through conscious representation), the method of selection 
makes use of direct conscious representation of modes of past 
activity. Images of previous movements are raised to the 
level of reflective consciousness and made to serve as a con- 
trolling agency. The new response then takes place under 
conscious control until it becomes fixed. Then consciousness 
tends to disappear. 

It is evident that consciousness is a factor in learning new 
responses. It is not needed in either the native or acquired 
reactions. There adjustments take place with automatic 
regularity. But where the native and the acquired adjust- 
ments are inadequate, there is need of a directive agency. 
In such cases the best endeavor of the organism is challenged 
and it responds with the highest power it possesses, that of 
consciousness. Such occasions furnish the opportunity for 
the most rapid conscious development. In fact, without 
these crises in the life of the organism no progress is possible. 
Unless new responses are constantly in process of acquire- 
ment, education ceases. So the greater the number of ad- 
justments required in the life of an organism, the higher the 
stage of development it will re9,ch. The organism that is 



CONSCIOUSNESS AND BEHAVIOR 409 

perfectly adjusted, i. e., has all the native and acquired re- 
sponses needed to meet its requirements, has reached the end 
of its conscious development. Perfectly formed habits, while 
they are useful in maintaining life on the level of its present 
attainment, do not serve to raise the organism to a higher 
level. It is only in the formation of habit that the process of 
education goes on. Practically no advance comes from the 
habitual modes of activities. Man's high development is 
due to the fact that he is continually forced to learn new 
habits of action in order to adjust himself to the world about 
him. He never becomes fully adjusted because, as he de- 
velops, his environment enlarges and changes, and conse- 
quently demands new responses. This requires the forma- 
tion of a large number of habits which must be continually 
broken up and reformed under the direction of consciousness. 
It is where his habits become absolutely fixed that he ceases 
to develop. For this reason long-continued operation of an 
automatic machine reacts deleteriously upon its operator. 
The man who works eight hours a day, month after month, 
upon such a machine is limited in his activities to a monoto- 
nous circle of habit which inhibits mental activity, and in the 
end lessens the plasticity of the nervous tissue, and therefore 
the possibility of reactions of a higher order. He thus finds 
himself caught in the net of habit. The deadening effect of 
automatic work upon the worker is greatest where the reac- 
tions are most habitual, and where the activities required 
are simplest and least varied in their nature. On the other 
hand, where the work of the day is varied — where the worker 
is called upon to make a large number of new and varied 
adjustments — there his mental fife is constantly being stimu- 
lated and his activity is educative. As we have already said, 
education lies in the process of forming new habits of behavior 
through conscious control, and development ceases when these 
forms of behavior become fixed. 

In the primitive method of learning through the trial-and- 
error method, the random motor activities always take the 



4IO PSYCHOLOGY 

direction of simplification and fixity with a decreasing accom- 
paniment of consciousness. But in the higher method of 
learning new responses through conscious representations, the 
volitional activities may take two directions: (i) Toward 
simplification, regularity, and fixity (habits), with decreasing 
consciousness and loss of plasticity; or (2) toward complexity 
and variability, with increasing consciousness and mental 
development. In the latter case, volitional activity is con- 
stantly enlarging its field of action and involving the mental 
processes of memory, imagination, deliberation, comparison, 
and judgment.^ 

Genesis of Motor Activity. — So far we have confined our 
attention to the motor activity as we find it going on in the 
individual organisms. We have seen that each individual 
inherits a stock of native reactions, out of which he builds his 
future behavior through the aid of consciousness. If we in- 
quire into the source of these native reactions we must pass 
from individual to racial development. How did these or- 
ganic reactions get formed in the first place? Were they 
originally conscious reactions from which consciousness has 
lapsed, or were they formed without the aid of conscious- 
ness? In other words, was consciousness present from the 
beginning of organic activity, or did it appear after the origi- 
nal forms of activity were in operation in the living organ- 
ism? The problem is partly biological and partly psycho- 
logical, but in neither science is there a sufficient basis of 
facts to solve it. Authorities differ in their theories: Some 
hold that consciousness was present at the beginning of 
organic life, and that the first movements of the first organ- 
isms were conscious movements. Later, when the move- 
ments became fixed, consciousness lapsed, and the forms of 
activity were then passed on to later generations by heredity. 
The instincts, for instance, are thought to be originally con- 
sciously controlled activities, which through repetition be- 
came so thoroughly ingrained in the organisms that they no 

1 James: "Principles of Psychology," chapter on "Habit," 



CONSCIOUSNESS AND BEHAVIOR 4II 

longer needed conscious direction. This theory of the origin 
of instincts is known as the "lapsed intelligence theory." 
The following facts are urged as evidence in support of the 
theory: 

1. Habits which are formed under the direction of con- 
sciousness may later become sufficiently automatic to take 
place without the aid of consciousness. Instincts may have^ 
been primitive habits which are preserved by heredity. 

2. Many of the purely physiological reflexes and instincts 
can now be modified by conscious direction. This fact sug- 
gests an original conscious control. 

3. Certain emotional reflexes, like raising the nostrils in 
contempt, are analogous to the primitive uncovering of the 
teeth in our semihuman progenitors when they were about 
to attack an enemy. The emotional reflexes may, therefore, 
be survivals of earlier conscious action.^ 

Other authorities believe that consciousness appeared in 
racial development after the physiological reflexes were in 
operation, and that the first movements were, therefore, un- 
conscious reflexes. The Spencer-Bain theory of the origin of 
consciousness holds that life was at first without conscious- 
ness. Consciousness appeared at a moment of neural stress 
in some unusually heightened or lowered nervous process — 
probably in both. Instincts, then, are the accumulation of 
unconscious adaptive reflexes preserved and chained together 
by natural selection. This is known as the "reflex theory of 
instincts." Consciousness was at first vague and indefinite — 
mere feelings of pleasure and pain — and only gradually be- 
came aware of the motor activities going on in the organism. 
Later it developed to the point where it could image and 
control certain of the reflexes. This marks the beginning of 
voluntary control. 

^Wundt: "Physiol. Psychol.," Ill, p. 279; "Outlines of Psych.," p. 213. 
Ward: Art. "Psychology." in Encycl. Brit., XX. Cope: "Origin of the Fittest." 
Titchener: "Textbook of Psychology," p. 452. Baldwin: "Mental Develop- 
ment," p. 208. 



412 PSYCHOLOGY 

The main objection to the first theory is that it seems to 
demand too high a state of intelligence in the first primitive 
organisms. Even if consciousness were present in the first 
organic movements, it seems impossible that conscious rep- 
resentation necessary for the control of movement could be 
present. The most that could be reasonably granted is a 
vague organic feeling which is inadequate as a directive 
agency. Certainly the very first movement of the first 
organism had no conscious experience back of it which could 
serve as a guide for its response. 

The second theory fails to make clear how a series of sim- 
ple reflexes were chained together when only the last reflex 
in the series brought about any gain for the organism. Again 
it is not clear how an organism which has been reacting with- 
out consciousness suddenly acquires it merely on the crest of 
the wave of heightened neural activity. 

Whatever the truth may be about the first reactions in 
racial development, the first reactions of the organism are 
not now consciously controlled. For some time the child is 
only vaguely aware of the native responses which are ex- 
pressing themselves without his direction. It is not until 
they have been going on for some time that he is able to take 
affairs into his own hands and control his behavior. 

The Connection Between Conscious States and Action 
— The Law of Dynamogenesis 

All forms of motor activity above the physiological re- 
flexes involve consciousness. The nature of the conscious- 
ness involved varies from mere suggestion to action to 
volitional control of behavior. In the native and acquired 
activities consciousness serves in the capacity of suggestion. 
In volitional activity consciousness controls as well as sug- 
gests activity. The most complete connection between con- 
sciousness and motor activity is found in volitional activity. 
So far as we are able to observe, nothing stands between the 
conscious representation of the act on the one hand, and the 



CONSCIOUSNESS AND BEHAVIOR 413 

execution of the act on the other. When the act or its con- 
sequences are imaged and the consent is given, the opening 
of the motor pathways in the brain seems to be completed 
and the act invariably follows. There is an immediate con- 
nection between consciousness and action. Some of the con- 
nections are native and some are acquired. We are born 
with definite tendencies to act in certain ways when certain 
conscious experiences come to us, and we acquire through 
experience definite tendencies to act in response to certain 
other conscious experiences. We may say, then, that every 
conscious state tends to express itself in some form of motor 
activity. This principle is known as the law of dynamo genesis. 
Any vivid image of movement always involves a motor 
impulse which tends to bring about the movement imaged. 
Imagine how it feels to bend the right forefinger and note the 
impulse to move it. In some cases the actual movement will 
take place without any definite intention to move the finger. 
But the image of movement is not always necessary. A 
large part of our daily activities are movements which follow 
all kinds of conscious states. Seeing my pen on the floor, I 
pick it up without consciously imaging the movement. If I 
suddenly remember that I have an engagement, I start for 
my hat and coat without thinking about what I am doing. 
Nearly every one has had the experience of performing some 
act unintentionally which had been thought of some moments 
before, but which had in the meantime dropped out of con- 
sciousness. The motor pathway was unblocked by the earlier 
thought, and the act appeared at the first opportunity. Just 
this morning I sat down at my desk with the intention of 
putting away some letters which I had in my hand. Hap- 
pening to remember an engagement which I had made, I 
took out my watch just as I sat down and noted the time, 
then opened the drawer of the desk and placed the watch 
where I had intended to put the letters. It often happens 
that in conversation we use some word or phrase just after 
determining not to use it for fear of offending a friend. The 



414 PSYCHOLOGY 

thought opens up the motor pathway, and if the conscious 
inhibition lapses for an instant the expression will take place, 
and when we come to, we realize that we have said just the 
thing that a moment before we determined not to say. In 
skilled movements there is oftentimes a strong tendency to 
repeat an error again and again immediately after its first 
appearance, simply because consciousness of the first error is 
still present in the mind. This consciousness acts as a pre- 
disposition to the movement. And so we could multiply in- 
definitely illustrations of the fact that mental states of all 
kinds make immediate connections with motor activity. 

This generalization may appear too sweeping. The im- 
plication that every idea which appears in consciousness is 
followed by a fully executed bodily reaction is, of course, not 
true. Evidently we have many thoughts which do not find 
expression in behavior. However, we have reason to believe 
that the tendency to movement is present in every mental 
state, even though the actual movement does not take place. 
The reason for its failure to appear rests in the fact that it is 
inhibited by the dynamic character of other mental states 
which rise in the mind at the same time. In the lower ani- 
mals mental states find immediate expression in motor activ- 
ity. In the more complex mental life of man the direct ex- 
pression of consciousness is often modified or inhibited. In 
the very young child, as in animals, mental states find imme- 
diate expression in motor activity. But gradually, as the 
simplicity of mental life develops into greater manifoldness 
and complexity, there arises the possibility of conflict between 
the impulses of consciousness. For instance, a young child 
with limited experience will grasp the bright flame of a can- 
dle if it is placed within his reach, but after he has experi- 
enced the painful quality of fire the grasping movement is 
inhibited. The impulse to reach for the flame is inhibited 
by the thought of ''burnt hand." 

The more complex the mental state the fewer are the 
chances for direct connection with motor activity.. But when 



CONSCIOUSNESS AND BEHAVIOR 415 

ideas are clear and definite, and no opposing ideas arise, they 
lead to action. Men of action are men with single and clear 
ideas. 

The connection between mental states and bodily activi- 
ties is such that the character of consciousness comes in time 
to stamp itself upon the physical appearance of the individ- 
ual. The outer man reveals the inner man so faithfully that 
we need not wonder at the revelations of the so-called ''mind- 
readers" — most of them persons who have learned the art 
of reading the character of thoughts by means of physical 
appearances and actions. 

If we consider for a moment the law of d5niamogenesis in 
the light of the history of the development of motor activity, 
we shall be able to get a still clearer view of the dynami'c 
character of consciousness. In the beginning every stimulus 
is transferred immediately into action. Through the process 
of evolution a simple nervous system is developed and set 
aside for the purpose of taking over the function of transmit- 
ting stimulation from one part of the body to another. Then 
the brain is built up as a receiving and distributing centre for 
nerve impulses. Now the brain retains the primitive irri- 
tability of tissue in that the nerve impulses which reach it 
from sense-organs are communicated to the organs of response 
— the muscles. The tendency to communicate stimulation is 
the same as in the primitive state, but the pathways by 
which transmission takes place are greater in number and 
complexity. Meantime consciousness has definitely appeared 
in connection with the activity of the brain centres. Sensa- 
tions and perceptions now aid in setting up immediate re- 
sponses to stimuli through the reflexes arid instincts. Later, 
conscious representation, comparison, and judgment appear 
and make possible the process of volitional activity by means 
of which nervous impulses may be directed into definite 
directions, or even inhibited. While consciousness has be- 
come a definite factor in the psychophysical activity, the 
primitive nature of nerve impulses has not been changed. 



41 6 PSYCHOLOGY 

There is the same tendency for every sensory stimulation to 
pass directly into action. Not only sensory stimulation, but 
thoughts and ideas corresponding to higher-centre activities 
show the same primitive dynamic character. 

Control. — Just as in the beginning simple conscious 
states were connected directly with organic responses and so 
served to control behavior, so now in its highest forms con- 
sciousness is still directly connected with motor activity. 
The rise of higher forms of consciousness has not changed 
the nature of control; it has only made it more complex. 
Rational control comes from the presence in the mind of 
systems of ideas which check and countercheck each other 
in such a way that the resultant forces run out into the par- 
ticular kind of behavior appropriate to the situation which 
has aroused the ideas. The control of our motor activities 
lies in the ideas which we allow to take possession of us. He 
who would follow a single plan of behavior must allow no 
ideas but those in keeping with the plan to get possession of 
him. If he does he will find that they will be real forces, 
tugging at the sinews of his action until in the end they will 
master him and force him to fight for them. 

Effect of Motor Activity upon Consciousness.— It was 
asserted in the beginning of the chapter that consciousness 
both determines behavior and in turn is determined by it. 
We may now briefly consider the second part of this princi- 
ple. The sensations of movements play no small part in the 
content of consciousness. Every movement of the voluntary 
muscles gives rise to kinsesthetic sensations which help to 
determine the character of consciousness. The simple ex- 
perience of smell is partly determined by the sensations of 
movement. If we carefully note the differences between 
movements (in nostrils, pharynx, head, respiratory actions) 
made when we are smelling some displeasing odor like that 
of asafoetida, and the movements made when we are smell- 
ing the odor of violets, we can easily detect the part which 
sensations of movement play in the experience. Sensa- 



CONSCIOUSNESS AND BEHAVIOR 417 

tions coming from the movements of turning the head away, 
stuffy sensation in pharynx from closing the back air-passages 
and inhibiting respiration, are present in the one case and 
absent in the other. The content of consciousness in making 
definite decisions of denial plainly contains the sensations of 
a peculiar muscular set and tension. The experiences of 
scorn, defiance, anger, and vast spatial dimension, contain 
very markedly characteristic groups of muscular sensations. 
Images of the words we use are usually in terms of the sensa- 
tions of movements made in speech. Part of the feeling of 
self consists in the sensations of motor reactions which are 
going on in our muscles. These sensations contribute a large 
share in determining our passing moods and emotions. 

In the growth and the development of consciousness, dif- 
ferentiation of motor responses is an important factor in 
breaking up and organizing vague states of consciousness 
into definite experiences. It is the child's motor reactions 
toward objects which make them definite things for him and 
set them off from other objects. His different ways of react- 
ing to objects analyzes the as yet undifferentiable world into 
elements of experience. He comes to know as one thing 
that to which he reacts with a single characteristic response. 
His notion of "chair" is determined by the fact that he sits 
upon it. His notion of "knife" is determined by the reac- 
tions of whittling; of "ball" by rolling, throwing, and catch- 
ing. Each object in his at first rather hazy world stands out 
the more clearly and distinctly as his reactions to it become 
more and more definite. The development and organization 
of the child's knowledge of the world proceed as he co-ordi- 
nates and controls his motor responses. In later develop- 
ment, even in the more abstract processes of thinking, clear- 
ness and orderliness of thought are the result of the forma- 
tion of clear-cut and definite modes of action. 

Now, while the sensations of movement stimulate con- 
sciousness, and contribute to its content and to its differentia- 
tion and development; there is another, more fundamental 



4l8 PSYCHOLOGY 

aspect to consider. This aspect is revealed in the fact that 
motor activity involves open and active brain pathways. 
The motor centres in the brain form a drainage area for the 
higher associational centres, and so provide for and invite 
greater activity in these centres. We often find ourselves in 
some situation where we are unable to collect our thoughts. 
Consciousness is at a standstill, and we remain empty-headed 
and inactive. Now if we start to say or do something, no 
matter what, just so we start the neural mechanism going, 
our wits come back to us 'and we gain control of the situa- 
tion. The action opens up the neural pathways in the 
brain. Anything that tends to block up these outlets of 
motor activity tends to decrease the chances for the rise of 
consciousness. The greater the opportunity for response, 
provided we take advantage of it, the higher the degree of 
mental development. 



CHAPTER XIX 

WILL 

Conation. — We have seen that consciousness is impulsive, 
i. e., leads to motor reactions. This dynamic aspect of con- 
sciousness is known as conation. Conation manifests itself 
in impulses and tendencies to action. The broadest use of 
the term conation has been made to include such philosophi- 
cal concepts as that of the "will to live," supposed to be a 
more or less blind innate tendency within us, by virtue of 
which we are impelled to life-preserving activities. The so- 
called "unconscious will" is also to be classed among these 
metaphysical conceptions of the fundamental conative aspects 
of consciousness. Such conceptions carry with them the im- 
plications that some cosmic purpose is constantly striving to 
realize itself through the conative tendencies. In psychol- 
ogy, however, conation is used in a narrower sense, indicating 
merely that consciousness is dynamic. Every state of con- 
sciousness tends to culminate in motor activity. This motor 
activity manifests itself in reflexes, instincts, ideo-motor 
movements, habits, and volitional reactions. Some of these 
forms of reaction are inherited and some are acquired through 
individual experience. Most of the reflexes and all of the 
instincts are inherited, while the ideo-motor activities and 
habits are acquired. These movements follow immediately 
upon the appearance of certain mental states. Thus the per- 
ception of a hot object is followed by the withdrawing reflex; 
the presence of the young is followed by the parental reac- 
tions; the sight of the door-knob is followed by the move- 
ments of opening the door; the sight of the keyboard of the 
piano and the music score is followed by the complex series 
of finger co-ordinations necessary to produce the music. The 

419 



420 PSYCHOLOGY 

reflexes, instincts, and habitual reactions are relatively fixed 
and invariable in character, while the volitional reactions are 
highly variable. 

We have noted that the acquired reactions have been 
built up in two ways: First, by means of the method of trial 
and error, in which the proper reaction comes out of a mass 
of random reflex and instinctive movements, and, second, 
by means of volitional control. Volitional action is a form 
of conation which we must examine more thoroughly than 
we have heretofore. In volitional movement we deliberately 
plan and purposely execute certain acts. All psychologists 
agree that these movements are, so far as they are themselves 
concerned, movements or combinations of movements, which 
the organism has already made, either in an instinctive or 
reflex way. Volitional activity then consists in the control 
of movements of which the organism is already capable. 

Will. — Is volitional activity marked off from the other 
forms of activities by a new kind of conscious element, dis- 
tinct from sensation and affection or any of their compounds? 
Does the control of volitional movements arise from a pure 
will element which does not appear in the non-volitional re- 
actions? So far introspection has failed to reveal any new 
and special content of consciousness which appears in the 
volitional activities and which can be looked upon as the 
will. Where observation has failed to give us facts, theory 
has attempted to supplement our knowledge. There are 
many theories about the will. Some of them, the spiritual- 
istic theories, consider the will as a manifestation of the 
transcendental ego which may act independently of the laws 
governing the empirical self. Some of them, the empirical 
theories, consider the will as the sum of the conscious im- 
pulses or directive tendencies found in the conscious states 
themselves. If we were to review the history of psychologi- 
cal thought, we should find that the will has been variously 
considered. At times it has been identified with the intellec- 
tual functions, again with the feelings and emotions, and still 



WILL 421 

again it has been considered as an absolute and independent 
function of the mind. Accordingly, the conception of the 
will has varied from the intellectualistic point of view, in which 
the will is derived from the cognitive processes, to the volun- 
taristic point of view, in which it is the central point of all 
consciousness and the basis of all mental life. It has been 
looked upon both as a form of feeling and as a combination 
of feeling and idea. The materialistic point of view has con- 
sidered the will simply as a combination of reflexes grown up 
in the course of evolution. According to this theory the will 
is developed out of the automatic reflexes which combine into 
more and more complex forms, while at the same time con- 
sciousness is developing to the point where it can take note 
of these movements and form kinaesthetic images of them. 
A clear-cut kinaesthetic image of a movement becomes the 
mental side of willing. Whenever, according to a modern 
form of the reflex theory, we image a movement clearly and 
vividly and hold it in mind before the movement takes place, 
we then feel that the act takes place by our own volition. 

The old tripartite division of the mind into knowing, feel- 
ing, and willing was based upon the "absolute theory of the 
will," which regarded it as an independent and co-ordinate 
elementary function along with cognition and affection. The 
tendency of modern psychology is to leave to metaphysics 
speculation about the ultimate nature of the will, and to 
confine itself to the study of specific volitional reactions for 
the purpose of determining empirically the nature of these 
reactions. 

We have already remarked in our discussion of "con- 
sciousness and action" that as far as we can observe, nothing 
in the nature of a unique will element stands between the 
consciousness immediately preceding a volitional act and the 
movement which executes it. We found that on the mental 
side there is either the image of the movement to be made 
(resident image) or the image of some result of the movement 
(remote image), and the consent or intention that the move- 



422 PSYCHOLOGY 

ment be carried out. Jarnes says that an anticipatory idea 
of the movement's sensible effect (resident or remote) and 
the fiat is all that introspection can discover as the conscious 
forerunner of a volitional act. By the fiat he means holding 
the idea before the mind to the exclusion of other antagonistic 
ideas. The prevalence of the idea in the mind terminates 
the willing and the act takes place mechanically. Only when 
ideas of competing or antagonistic acts arise does the will 
manifest itself. Then the strain of the attention to hold one 
of the ideas before the mind is, according to James, the fun- 
damental act of the will. The will is therefore a psychic act 
— to fill the mind with the idea, to keep affirming and adopt- 
ing a thought which if left to itself would slip away — that is 
the inward volitional act, says James. Accordingly, volition 
presupposes deliberation in which different alternatives are 
presented to the mind. These rival lines of action alternate 
in consciousness — first one and then the other is attended to 
— until attention finally fixes upon one to the exclusion of all 
others. The decision or choice is the holding of the given 
idea of action fast in the mind. When this is done we con- 
sent to the reality of the idea. 

Many psychologists beheve that the control of move- 
ments is primarily brought about through the effect of the 
kinaesthetic images (resident images) of the movements. The 
image of the movement in some way unblocks the neural 
pathways leading to the proper muscles and the nervous 
energy drains into them and brings about the movement. 
Recent investigations of the control of movement indicate 
that more prominence should be given to the sensations 
awakened by the movement itself as a factor of control in 
the following stages of the movement. The control of a 
movement requires awareness of the position of the parts of 
the body moved before the movement begins. This means 
that each moment of kinaesthetic sensory experience becomes 
the cue for the following movements. This becomes very 
evident if we note the contents of consciousness during the 



WILL 423 

act of throwing at a mark or in jumping. Here the control is 
brought about more by present sensations than by images 
of past movements or by images of previous results of similar 
movements. Moreover, not only the sensations of moving 
muscles, but the more remote visual sensations coming from 
the target, the height from which we are to jump, and other 
characteristics of our surroundings, are important factors in 
the control of movements. As we have previously indicated, 
pathological conditions in which the sensory nerves from the 
muscles are so affected that the patient cannot sense the 
movements or positions of the parts of the body, result in 
the inability to control movements, although the motor 
nerves running to the muscles from the brain are intact. 
Lack of sensations of movement means lack of control of 
movements. Such a condition is found in cases of locomotor 
ataxia. 

Neither the anticipatory image of an act (resident image) 
nor the image of the result or consequence of the act (remote 
image) nor the kinaesthetic sensations of the movements con- 
stituting the act give us a new form of consciousness which 
we can call a will element. If there is such a thing as a pure 
will element in consciousness it has been playing hide-and- 
seek with us. A few paragraphs back we said there were cer- 
tain exceptions to the statement that in careful experimental 
work on the will introspection had failed to detect any special 
will element in volitional activities. Ach and Michotte claim 
that they are able to detect a will element which is present in 
all volitional activities. They report that they find what 
they call an actual moment in which there is a content which 
can be described only by the phrase "I will actually." They 
claim that this conscious content is that of a subjectively de- 
termined act — a pure will act. This is found only in voli- 
tional acts and differentiates them from all other forms of 
action. In this "actual moment" the "I" is taken as the 
cause of the reaction, and therefore we are conscious of an 
egoistic control, or self-determined act. It is rather difficult 



424 PSYCHOLOGY 

to determine Just how far the metaphysical conception of the 
self or subject of consciousness has influenced the introspec- 
tion in these cases. There is no questioning the fact that in 
volitional acts we feel that we are originating and determin- 
ing the movements. James refers to this experience as an 
illusion, and Miinsterberg considers it merely the anticipatory 
consciousness of the act. Other psychologists who hold that 
consciousness is a real agency operating between the recep- 
tion of stimuli and the motor response, and therefore effective 
in determining behavior, believe that the will element is to 
be found in certain directive tendencies of consciousness 
which they claim transcends the limits of a mere assemblage 
of elements. The " imageless- thought psychologists," some 
of them at least, are inclined to believe that the control of 
volitional movements may be brought about by a pure 
thought element which is a directive conscious tendency over 
and above the conscious contents of sensations and anticipa- 
tory images of the movements. Ogden, for instance, in his 
"Introduction to General Psychology," has outlined an inter- 
action theory of mind which admits a purposive activity in 
consciousness. This active principle works independently of 
the laws of association and is, therefore, a new determining 
factor in consciousness. Thus we have a basis for the will. 
He recognizes three modes of directive tendencies: First, 
physiological impulses found in the reflexes; second, directive 
tendencies which arise from association complexes, such as 
those found in habits of action; and third, egocentric tenden- 
cies in which we are conscious of a "personal moment" as 
directing the course of our thinking and acting. Hence we 
have real self-activity which is a direct manifestation of the 
ego. While some of our activities are the result of a physio- 
logical casual order, and some are the result of the laws of 
association, yet a direction can be given to these activities 
by the purposive or egocentric tendencies. This conception 
of a directive tendency in consciousness is an attempt to 
escape a purely mechanical conception of life in which con- 



WILL 425 

sciousness must be considered as a mere epiphenomenon — a 
spectator of what is going on, but in no way effective in de- 
termining the course of behavior. 

Will as Self-Determination. — It is quite plain that the 
most popular way of thinking about the will is to consider it 
as the activity of a self or ego. It is the self which makes 
our decisions for us and determines the kind of behavior 
manifested in our volitional acts. Now such a conception 
involves the metaphysical subject side of consciousness to 
which attention was called in the first chapter of the book. 
It was there pointed out that it is only the content side of con- 
sciousness that can be observed. We have no empirical 
knowledge of the subject or ego which is supposed to know 
and feel and will for us. Only the content of consciousness 
is revealed to introspective observation. If, therefore, sortie 
one asserts that the self does our willing we are unable to 
affirm or deny the statement upon the basis of observed facts. 
If it seems reasonable to believe that back of the conscious 
states themselves there is a self or ego which is responsible 
for them, then we must consider it only as a theory and not 
as a fact. What we really need to know, however, is what 
the will is as content of consciousness. So far we have been 
unable to find any unique and separate will element on the 
content side of consciousness beyond the resident and remote 
images and sensations preceding and accompanying our voli- 
tional acts, and the consciousness of a purpose or intention. 
These are all cognitive factors. 

It has been suggested that in all cases where we exert will 
power to decide upon some line of action, we feel the effort 
of the will. Is this not the will element or content that we 
have been looking for? It is generally agreed, however, that 
this feeling of effort in volitional activity is the sensation of 
muscular strain coming from the forehead and chest and 
other parts of the body during the moments of deliberative 
attention required in deciding between alternative courses of 
action. We know that at such times we innervate certain 



426 PSYCHOLOGY 

muscles, especially those of the head and those controlling 
the respiratory organs. 

It has also been suggested that the so-called "feeling of 
innervation" is a will factor or representation of the will 
consciousness. The feeling of innervation is supposed to be 
the consciousness of nervous energy or nerve impulses sent 
out from the brain centres to the appropriate muscles, whose 
activity is required in carrying out volitional acts. If we 
were not able to sense this outgoing nerve energy, how could 
we tell how much to send out and to what particular mus- 
cles? It is claimed that in volitional movements we are 
conscious in advance both of the amount and the direction 
of the nervous energy involved in the movements, and that 
this consciousness is the feeling of innervation. Here is a 
first-hand conscious content which apparently originates in 
and is controlled by the will, and not the conscious content 
made up of images of past movements, as our analysis has 
shown the contents of volitional consciousness to be. But 
the doctrine of the "feeling of innervation" has not been 
accepted. There is no evidence that we are in any way 
aware in advance of the nervous discharge from the brain 
centres to the muscles. James, who does not believe in the 
"feeling of innervation," says: "The discharge into the 
motor nerves is insentient, and all our ideas of movement, in- 
cluding those of the efifort which it requires, as well as those 
of its direction, its extent, its strength, and its velocity, are 
images of peripheral sensations, either 'remote,' or resident 
in the moving parts, or in other parts which sympathetically 
act with them in consequence of the diffusive wave."^ We 
are, therefore, just where we were in the beginning of our 
search for a self-determining consciousness, or will content. 
The feelings of effort and whatever there is of observable 
experience in the "feeling of innervation" are kinaesthetic 

* "Principles of Psychology," vol. II, p. 493. For a refutation of the doc- 
trine of the feeling of innervation the student is referred to pages 493-518 of 
that volume. 



WILL 427 

sensations originating in muscular strain. They are, there- 
fore, not consciousness of the will. 

If we discard the older metaphysical view of the self as a 
subject or ego, and look upon the self (from the content point 
of view) as an organized body of conscious content made up 
of knowledge, thoughts, desires, and ideals which have grown 
up through experience and have formed a nucleus, or per- 
sonality, we may be able to get a clearer conception of the 
volitional process as a self-determining activity. First of all, 
however, we must understand that the act of willing is a 
psychical process. The physical movements which carry out 
the inner will process are merely the physiological results of 
the willing. The settling of the mind upon a course of action 
and holding it fast in the field of attention, that, as James 
has said, is the real act of will — the fiat, or settlement by the 
self of a mental issue. Now, what idea gains the attention 
and holds it and, therefore, finds expression, depends upon 
the nature of the knowledge, thoughts, desires, and ideals 
which make up the self. Whatever idea is felt as foreign to 
the empirical self at the moment of decision, is rejected, but 
whatever idea is in harmony with the self uppermost at the 
time is reinforced by the self-feelings and becomes identified 
with the self. In a more popular way we say that we are 
interested in certain things and ideas — that a given idea is 
at the time the most interesting project before us. It is, 
therefore, the nature of the self which determines what addi- 
tions to itself are to be made. Whatever fits harmoniously 
into the system of conscious states which constitutes the self 
at the time is accepted. The impelling force of an idea or 
imaged line of action is determined, therefore, by the self 
and the selection or choice of action is made by the self. 
Sometimes only a small and fragmentary part of the self is 
active in making its decisions. Overhasty actions result. 
In such cases the volitional process is not representative of 
the true self. A passing desire may be indulged, or an idea, 
illuminated by the momentary flash of passion, may be given 



428 PSYCHOLOGY 

the right of way before all the forces of the self are given time 
or opportunity to take part in determining the issue. A per- 
sonality which allows a single idea, or the first thing that 
enters the mind to find expression before it can be reviewed 
by the larger self, may be said to possess an impulsive will 
or an "explosive will," as James puts it. Defective inhibi- 
tory powers are found in such a personality. The will in the 
larger sense functions not only in a positive way in bringing 
about co-ordinated action, but also in a negative way by 
checking or inhibiting impulsive action. Isolated ideas and 
desires (ideas and desires not fully co-ordinated with the 
organized body of knowledge) are impulsive, but when the 
ideas are organized and the desires co-ordinated into a sys- 
tem, so that each is fixed in relation to the others, then the 
impulsive character of this larger self becomes volitional. 

Since the self is a very complex conscious organization 
(containing tendencies, impulses, and desires, some of them 
native and racial and some of them acquired and ideal), con- 
flicts between the different tendencies, impulses, and desires 
are sure to arise. The self is then arrayed against the self. 
No issue can take place until the conflicting and antagonistic 
parts of the self are reduced to a single system of impulses. 
This may take place- either by the suppression of all but one 
group of impulses, or by the union and modification of all 
the impulses into a single system. Volitional control really 
consists in the acceptance of ideas by the organized body of 
conscious states, which we have called the self. Will is not 
a new and separate mental element existing alongside our 
other mental elements, nor is it a mental factor which by its 
own force represses our instinctive tendencies and primitive 
impulses, but it is the conative or dynamic side of all our 
consciousness in so far as it is organized into a united self — 
as Angell expresses it, "The whole mind active, this is the 
will." 

Will and Knowledge. — From the foregoing it is evident 
that the exercise of the will presupposes a supply of ideas. 



^ WILL 429 

left in the mind by previous experience. In fact there is no 
will apart from knowledge. It is just at those points where 
our information is meagre that we show weak conative ten- 
dencies. We hesitate and waver and delay in taking a de- 
cided stand when we do not possess definite knowledge. We 
are most easily influenced by agencies outside our own self 
under such conditions. On the other hand, we are most de- 
cided just where we have mastered the facts about us. In 
many cases, however, we are not master of the facts and we 
must decide the issue from a limited point of view. All that 
can be expected under these circumstances is that we make 
use of all the possibilities within us — that we bring to bear 
upon the problems all the relevant knowledge we possess, to 
the end that our decision springs out of the whole self and 
not out of a fragment of it. The man with a healthy and 
vigorous will is the man whose knowledge is varied and ex- 
tensive enough to allow him to look on all sides of any given 
question calling for his decision. To be able to think clearly 
is a necessary attribute of a prompt and forceful will. On 
the other hand, hazy knowledge leads to doubt and indeci- 
sion, which is the characteristic of a weak and inefficient will. 

Will and Character. — While it is true that the nature of 
our volitional action depends upon the kind of character we 
have, it is probably even more fundamentally true that the 
kind of character we develop depends upon the will. For 
character is the fixation of modes of willing — choices organ- 
ized into habits. Every decision made adds to and strength- 
ens the self in the particular Hne of thinking and acting which 
is involved in the decision. The man who has led an up- 
right life is unable to will a dishonorable act. The character 
of his self has been formed by years of willing, according to 
the principles of honesty and square deaKng, and these prin- 
ciples have become so important a part of his self that they 
are always on hand on all occasions of deliberation and choice. 

Freedom of the Will. — We cannot take up a discussion of 
the freedom of the will without entering into philosophical 



430 PSYCHOLOGY 

considerations. Within the limits of scientific psychology we 
have no method of approaching the larger question of the 
freedom of that system of conscious states, which make up 
the self, and which is supposed to be dominated by the will. 
As far as we know, all the observable elements which consti- 
tute the self are definitely and causally related to each other 
and the rise and fall of the elements within the self takes place 
in an orderly way, according to psychological laws. We can 
find no conscious element which is not subject to these laws. 
Freedom in the sense of absence of law is a conception which 
transcends the limits of psychology. But since the question 
of the free will is bound to be raised in the minds of those 
who approach the study of the will for the first time, we can 
profitably give it a brief consideration in order that we may 
at least understand the nature of the problem. Although we 
believe that we are free to choose between different lines of 
action, we shall find when we examine the matter carefully 
that there are many difficulties in the way of this belief. 

There are two philosophical theories about the freedom of 
the will: First, determinism, and, second, indeterminism. 
Determinism holds that every will act comes out of pre-exist- 
ing conditions of the self. According to this theory, we are 
bound to choose in accordance with the nature of the self. 
Our will is determined by our interests, desires, and ideals, 
which depend upon what we inherit and what we acquire 
through experience — upon what we are by nature and what 
we are by nurture. No one is free from these influences. In- 
determinism, on the other hand, holds that the will is not 
determined by previous conditions and surroundings of the 
self. The most radical form of this theory considers that 
will is absolutely independent of any motive for action what- 
ever. According to this theory, it is the will which determines 
motives for actions, while the will itself is not bound in any 
way. No antecedent condition of the self has anything to 
do with the will. What I will to do, for instance, is unpre- 
dictable even by an intelligence that is acquainted with my 



WILL 431 

entire past experience and the native characteristics inherited 
from my parents. 

Since psychology looks upon the self as a system of con- 
scious elements which has grown up in a rational way, and 
can be accounted for by psychological principles, it is evi- 
dent that we cannot accept the theory of indeterminism. A 
wholly free and capricious mental element which is not influ- 
enced by pre-existing conditions and present surroundings is 
beyond psychological explanation. In a certain way we may 
think of the will of man as free, especially when we compare 
him with the lower animals. The animals are controlled much 
more than we by the conditions of the present moment, 
since their behavior depends upon the nature of the present 
stimulus. Man, on the other hand, is not, as they are, the 
puppet of the moment, but transcends the immediate condi- 
tions of his environment. He is free from the demands of 
the moment in that he is able to recall past experiences, for- 
mulate them into principles and ideals, and use them as guides 
or cues of action. He may, therefore, adjust himself to more 
remote conditions which are not present in the immediate 
environment. In this sense man is free in just so far as 
his action springs from the broader field of past experiences 
rather than from the narrower experience of the present 
moment. 

Psychologically considered, every volitional activity can, 
if we know all the facts surrounding it, be fully accounted 
for by psychological principles. Really the only meaning of 
the term "free will" that is compatible with the principles 
of psychology is that which considers the will free in so far 
as it is not constrained by external factors but has the oppor- 
tunity of following out its own nature. In so far, then, as 
we are not subject to influences external to ourselves and can 
act according to the dictates of our own nature, we are free. 



CHAPTER XX 

THE SELF 

The Unity, Continuity, and Identity of Personal Conscious- 
ness. — So far, we have been engaged in the task of examining 
conscious life in a piecemeal fashion. In each chapter we 
have isolated and described some one aspect of consciousness, 
neglecting for the time its other aspects. This analytic pro- 
cedure is necessary in order that we may come to a better 
understanding of the whole conscious organization. But we 
must not stop here, for the discrete mental elements have 
no meaning when standing alone. As a matter of fact, we 
never find a sensation, a percept, a memory, a reasoning 
process, a feeling, an emotion, or a will act existing by itself. 
Sometimes one of these aspects of consciousness is dominant 
and sometimes another, but whether it is perception, or 
memory, or emotion, or reasoning, it is not the only mental 
state or process present at the moment. In each case there 
is something more — a background of consciousness represent- 
ing an organized and unified content which hangs together in 
a unique and personal way. Whatever is thrown upon the 
surface of consciousness is projected there momentarily as a 
lesser content upon a larger and more persistent content. 
No single experience stands alone in consciousness, but is 
outlined against other experiences which lie outside the focus 
of attention. Organic and bodily sensations, aches and 
pains, marginal visual and auditory presentations, fading 
images of experiences just past, memories of remote or recent 
scenes, hopes and desires and plans for the future make up 
this background. If, for instance, the messenger-boy hands 
me a telegram announcing the death of a friend, the emotion 
which the news produces and the thought concerning the 

432 



THE SELF 433 

future of his family are both experienced within the larger 
conscious content of myself writing a chapter on the self, 
plus the visual appearance of the top of my desk and the 
familiar sound of my neighbor's children playing outside; 
plus the feeling of hunger resulting from a delayed luncheon. 
All these experiences and many more lie in the background 
of the consciousness which is experiencing the emotion. 

Then, too, consciousness is not made up of a series of 
separate and discrete mental states. On the other hand, 
there is a marked continuity in the different experience of 
every individual. Each experience overlaps the experiences 
which precede and follow it, so that there is a continuous 
unity in each individual stream of consciousness. As new 
and different experiences appear they do not come as sharp 
breaks in consciousness but as modifications of the growing 
unity of experiences. The growth of the cumulative experi- 
ence is so gradual that there remains a sufficient conscious 
background of old experience to give the whole a self-identity. 
There is no moment in the normal waking life where this 
unity, continuity, and identity of conscious experiences can 
be disregarded. There is, then, an organization of experience 
into a personal unity in which all aspects and processes of 
consciousness are represented. This complex organization is 
the self. 

The Subject Self, or Ego. — From the very earliest times 
philosophers have noted the unity, continuity, and identity 
of the personal consciousness and have sought to explain this 
unity by assuming that back of the conscious states them- 
selves there exists for each individual a single unanalyzable 
subject self, or ego, to which the various parts of his experi- 
ence are presented and unified. Without this self, or ego, 
there would be, it was thought, no means of binding together 
the different elements of experience into any kind of unity; 
and further, without such a unifying entity, there could be no 
continuity or identity of experience. The idea of the dual 
nature of the self rests upOn this logical assumption, and has 



434 PSYCHOLOGY 

found its way into popular thought. It seems reasonable to 
suppose that all the various experiences of an individual must 
be presented to some single subject self whose function it is 
to organize them into a personal whole. James refers to the 
two aspects of the self as the ^'knower'' and the "known" or 
the "/" and the "me." Kant uses the terms pure ego and 
empirical self to designate the subject side and the content 
side of the self. 

The difficulty with such a conception of the self in psy- 
chology lies in the fact that the subject self or ego eludes 
observation, and the statements concerning it can never be 
checked up by actual experience. If we adhere strictly to 
the facts of conscious life, we must give up the conception of 
the transcendental ego, or subject self, and turn to the con- 
tent side of consciousness and try to find the principles of 
unity, continuity, and identity of the self, in the experiences 
themselves. We can, I think, make out a self purely on an 
empirical basis. We shall then have no need for the meta- 
physical conception of a self back of, and independent of the 
mental states which constitute actual experience. 

The Empirical Self. — If the discrete mental states cannot 
be attributed to an independent self, or psychical being be- 
yond the mental states themselves, then they must be attrib- 
uted to the empirical self, or complex of mental states — to 
that complex which constitutes the relatively invariable and 
persistent background of our conscious life. The empirical 
self is that central and intimate core of conscious content 
made up of the bodily sensations, familiar thoughts and ideas, 
memories, feelings, and desires. If now we grant to this 
background of consciousness, activities, tendencies, and im- 
pulses, then we have a self-active conscious content which 
is capable of taking up new content into itself. In this way 
the empirical self takes on the function of the "knower." 
The dynamic aspect of the self is determined by the nature 
of the elements entering into the conscious states dominant 
at any one moment. Since all consciousness is functional 



THE SELF 435 

the self-content is also functional. The empirical self is, 
therefore, never simply a passive self, for while it is receptive 
in so far as it receives new content, it is also active in so far 
as it incorporates or apperceives this new material into the 
old. The conception of the self as passive is limited to the 
self when it is receiving impressions from without, as in sen- 
sation and perception. Even here the reception of impres- 
sions from without cannot take place without apperceptive 
activity of older experiences already in the mind. The cen- 
tral mass of content is always active in some degree. It is, 
of course, most active and directive in acts of will. 

The identity of the empirical self is manifest in the fact 
that no content can be assimilated without a body of old 
experiences which serves as a basis of interpretation. The 
fact of recognition in itself is evidence of the activity of the 
empirical self. The unity of the empirical self, together with 
its continuity and identity, we have already pointed out in 
the first paragraph of the chapter. We have attempted to 
make plain the fact that the conscious content of any single 
moment is not in itself a mere jumble of separate mental 
states, but an organized unity possessing active tendencies. 

Origin and Growth of the Self. — The question of the ori- 
gin of the self goes back to that of the origin of consciousness 
itself. We have assumed that consciousness was present 
from the very beginning of the individual's life. In the very 
earliest stages of life there was no organization or differentia- 
tion of conscious experience. The little consciousness which 
existed at that time was probably only a crude and unformed 
state of awareness. The first experiences to take form were 
those coming from the body and its organs (the bodily and 
organic sensations and pains, such as the cutaneous and 
muscular sensations, the sensations arising in the action of 
the heart and lungs, together with those of hunger and thirst,, 
the vague bodily desires and impulses, and the simple affec- 
tions). Certain of these recurrent experiences formed them- 
selves into the nucleus of the self. Gradually as conscious- 



436 PSYCHOLOGY 

ness of the body and its surroundings became clear and defi- 
nite, certain experiences were by their very nature more inti- 
mate and personal than others and these made up the threads 
which were gradually woven into the inner strands of the self. 

The outlines of the self, which at first included only the 
bodily experiences, gradually expand as knowledge of the 
world and our relation to it increases, so that the self comes 
to embrace a larger and larger content. The self-feeling 
starting with our body extends to our clothing and personal 
belongings, our family, our friends, our club, our country, 
and many other things which come in time to be identified 
with the self. The growing idea or appreciation of the self 
gets a social impress very early in its career, since the idea 
of self is determined largely by what we think others think 
of us and ours. Our self-consciousness is influenced to a very 
marked degree by this picture which we imagine others form 
of us — of our expressed thoughts, likes and dislikes, desires, 
habits, and behavior, of our financial standing and social 
position, our family, our friends, and so on. This picture of 
ourselves which we think exists in the minds of others is a 
constant factor in the contents of the self and it is implicitly 
present at all times. There is some truth in the popular 
statement that we are what others think of us. The func- 
tional aspects of the self are also influenced by the social 
factor. For it is a matter of common observation that we 
tend, in what we accomplish, to measure up to the ideas 
which others form of our ability. The social factor is a most 
important element in the growth of the self. 

No sketch of the origin and growth of the self is complete 
which does not consider the native impulses and instinctive 
activities which are antecedent conditions of the self. They 
not only form the basis on which the self builds, they also 
continue throughout the growth of the self. They color and 
modify it. The core of the self is the perpetual background 
of organic sensations, which with the instinctive impulses and 
aetivities constitutes the beginning of the self. As new ex- 



THE SELF 437 

periences make additions to the self on the conscious side, 
the formation of habits adds to the reflex and instinctive im- 
pulses of the self on the dynamic side. The self must be 
considered not only as a group of conscious states, but also 
as a mass of habits, instincts, tendencies, and attitudes. 

Contents of the Self. — Among the most important factors 
of the self is the persistent group of tactual, kinassthetic, and 
organic sensations, especially the sensations coming from the 
viscera. In certain cases where pathological conditions have 
changed the nature of the visceral sensations, there is a notice- 
able change in the patient's sense of personality. He feels 
like a different individual. The visual sensations of the ap- 
pearance of the body are also a factor in the contents of the 
self. To these elements we may add our settled likes and 
dislikes. Even the consciousness of external belongings enters 
into the content of the self, James has suggested that our 
clothing, our stocks and bonds, our horses and bank-accounts, 
our family and friends belong in the idea of self in so far as 
we are conscious of them in relation to our self. These latter 
factors involve the social element. It is the consciousness of 
these things as we think they appear to others which is im- 
portant in our idea of self. 

The factors which contribute very largely to the sense of 
personal identity and continuity are memory and the organic 
sensations. The fact that we can reproduce former experi- 
ences and identify them as our own serves to bridge over 
what would otherwise be serious breaks in our personality. 
In certain cases where the strands of memory are broken off 
altogether the sense of identity is lost. The bodily sensations 
are fairly constant and continuous and so contribute a thread 
of identity to the experience of self. There are other factors 
involved in the consciousness of the self, but in general we 
may say that the self-content is a persistent and slowly 
changing conscious complex in which the elements just men- 
tioned are central and constant. In normal individuals the 
central self-contents manifest no sudden changes, or abrupt 



438 PSYCHOLOGY 

breaks, although there may be considerable shifting of the 
peripheral contents corresponding to the different aspects of 
the self as manifested under different conditions.^ 

Consciousness of the Self. — So far we have discussed the 
self as a central and persistent core of conscious content. 
We must now consider the manner in which this self-content 
is differentiated and set apart from the other contents of the 
mind. How does the individual come to think of certain of 
his experiences in a personal and self-conscious way — as hav- 
ing an egoistic reference, while other of his experiences are 
given a non-egoistic reference? It is quite evident that 
whatever the origin of "self-feeling" may be, it is the self- 
feeling that determines what conscious contents are set aside 
to constitute the self. Before self-consciousness arises no 
self can be said to exist, for then all experiences are non- 
personal and neutral. 

The young child makes no distinction between the self 
and the not-self. Indeed, he does not distinguish at first 
between objects and persons. Gradually, however, it dawns 
upon him that certain objects (persons) in his environment 
react in a peculiar and unique manner, unlike the rest of the 
objects about him. Persons minister to his needs in a way 
that objects do not. They wash and clothe and feed him. 
They are peculiarly sensitive to his own acts and modes of 
experience. At the same time they are capricious in their 
movements. Sometimes they come when he cries and some- 
times they do not. Moreover, they come and go without 
warning. The child is, therefore, made aware of a certain 
independence and self-initiative in others which is reflected 
back to himself. He begins to be conscious of his own inde- 
pendence of action. From this point on he both identifies 
and contrasts his acts with the acts of those other objects 
which he comes to know as persons. The development of 
self-consciousness and the consciousness of others go hand 
in hand. Self-consciousness is, therefore, a social product 

^ See discussion of the self in chap. I, p. 17. 



THE SELF 439 

brought about through the contact with other persons and is 
the counterpart of his consciousness of other selves. What 
he discovers in others he reads into his own self, and what he 
finds in himself modifies and enriches his consciousness of 
other selves. What other persons think him to be (as mani- 
fested in their behavior toward him) is reflected into his own 
self. What he comes to think of himself he therefore finds 
in the minds of others. 

The Self and Sensation. — Having so far regarded the self 
as a synthesis of elements into an organized whole, we may 
now reverse the process and consider the self in relation to 
some of the discrete elements which constitute it. First of 
all, we shall consider sensations, the simplest kind of con- 
scious content which enters into the self. Hume, the gr^at 
champion of the empirical method, denied the existence of a 
self in the form of innate ideas prior to concrete experiences, 
and held sense-perception to be the source of all conscious 
life. In the beginning, consciousness is simply a vague ac- 
companiment of bodily existence, but as sensory presentations 
multiply, certain presentations break through this primitive 
vagueness and, together with their affective qualities, they 
are combined into a mental organization which begins to 
supplement the reflex and instinctive impulses by supplying 
new impulses of a sensory character. The relation between 
this beginning conscious-complex and new sensory experiences 
is twofold: First, the discrete sensory experiences furnish 
a fund of new material which serves to clear up the older 
experiences stored up in the complex. Secondly, the self, or 
organized complex, not only receives these separate sensa- 
tions, but it goes out to meet the new experiences, selecting 
and coloring them in accordance with the experiences already 
crystallized within it. The self, therefore, does not grow 
simply by accretions of new sensory experiences, but grows 
by its own selective activity, in the sense that it assimilates 
only those sensory elements which harmonize with it, and for 
which it is already prepared. 



440 PSYCHOLOGY 

Self and Perception. — This assimilative character of the 
self is seen to better advantage in perception. Perception, 
as we have already seen, is an arousal of old experiences 
within the self by newly entering sensations. In perception 
the self supplements any discrepancy in the new presentation 
by supplying it with material in keeping with its own nature. 
The directive influence of the organized complex of past ex- 
perience is plainly apparent in perception. 

Self and Attention. — The organization and growth of the 
self takes place very largely within the field of attention. 
This is so because attention determines what presentations 
enter consciousness and how they are to combine with the 
conscious elements already in the mind. Attention and the 
self are not, however, two different factors. Fundamentally, 
attention is the clearest and most active portion of the self- 
content. We may agree to the statement that attention is a 
manifestation of the self provided the metaphysical assump- 
tion of a subject self is not implied. For only those things 
enter consciousness, arouse and hold attention, that possess 
some elements of similarity to the already assimilated con- 
tents of the self; or are in some way represented within the 
self. In the earliest stages of individual development the 
self manifests itself through primary or spontaneous attention 
determined largely by native and instinctive propensities. 
Later spontaneous attention is a manifestation of a closely 
knit organization of habitual experiences and acquired ten- 
dencies. Interwoven with these native and acquired self 
actions is secondary or voluntary attention, determined by 
a new and consciously formed organization of experience. 
While spontaneous attention is an expression of what the 
primary and habitual self really is, voluntary attention ex- 
presses the conscious effort of the self to reach a higher stage 
of development. 

Self and Interest. — In the chapter on attention we saw 
that interest as a psychological content is dependent upon 
attention in that it gomes into existence only after attention 



THE SELF 441 

has been directed toward some object or topic of thought. 
That one's interests are a key to his real self is a common- 
place, but it is even more evident when we consider that 
interest is aroused by those things which readily catch and 
hold the attention. We are interested in the things which 
find affinities already within the self. Our interests, there- 
fore, represent both the native and acquired characteristics 
of the self. As the self develops they follow the lead of vol- 
untary attention and the simple affective states of pleasant- 
ness and unpleasantness. 

Self and Feeling. — There is a tendency in certain quarters 
to look upon the self as a "feeling-complex," with affection as 
the fundamental background or real unifying principle in the 
self. Accordingly, the real self is considered to be an organi; 
zation of affective life which manifests itself in the apprecia- 
tion of values in the things about us rather than in the in- 
tellectual apprehension of the things themselves. The real 
world is a world of values and the real self is a feeling-com- 
plex, and its relation to the world is an affective, not a cogni- 
tive one. However attractive this may be as a philosophy 
of the self, it finds little psychological support. While it is 
true that the self does manifest itself as "feeling" or affec- 
tion, it is never purely affection and nothing else. Indeed, in 
the author's opinion, there is no reason to consider the affec- 
tive phase of the self as fundamental. The self is certainly 
never purely a single phase of consciousness. It is just as 
truly a sensation-complex, an attention-complex, a knowing 
or willing complex, as it is a "feeling-complex," and each of 
these phases contributes to the more ultimate complex — the 
seff. 

It is true that the strong feelings or emotions appear to 
affect the self more than any other conscious content. An 
emotion seems to shake the self to its very foundations. The 
explanation of this rests not in the fundamental or deep- 
seated character of the affective elements, but in the inhibi- 
tory effect of the emotional stimulus upon the cognitive 9.C- 



442 PSYCHOLOGY 

tivity of the self. We are familiar with the Wofold relation 
between the self and newly entering material. First, the new 
material, perceptual or ideational, commands entrance to the 
self-content. Secondly, the self-content goes forth to mec'. 
the new experience, or, as we have said before, reacts to i 
and determines by its reaction the nature of the final impres- 
sion. Now, in the case of emotions the apperceptive side of 
the self is taken oflf its guard, so to speak, and the second, 
or efferent movement of the self, is inhibited. As a result, 
the incoming impulse from the stimulus permeates at ran- 
dom through, perhaps, the entire self-content, causing a mass 
of random and diffused motor reactions which characterize 
the emotional seizure. One must not mistake the spectacular 
reactions of emotion for a fundamental movement of the self. 
Really, emotion or feeling is not related to the self, as it is 
sometimes claimed, in any more basic way, nor does it make 
up the contents of the self any more fundamentally than do 
cognitive states of consciousness. 

Self and Will. — We have already called attention to the 
changing character of the self. Now one aspect of the self 
is prominent and now another. The self consists of a more 
or less changing complex of active impulses, desires, pur- 
pyoses, thoughts, feelings, and bodily sensations. These are 
projected against a relatively more stable and invariable 
background-content made up of habitual modes of thinking 
and feeling which, although not always active, are neverthe- 
less potential in the self. Thus we may distinguish between 
the immediate, or present self, consisting of the contents 
active at the moment, and the more remote or total self, in- 
cluding dispositions laid down by past experiences which are 
drawn into the present self in varying degrees at any mo- 
ment. Now the self that determines action and manifests 
itself in volition is the present self. What a man does in a 
volitional way depends upon what elements of his potential 
self are active in the present self at the time of his decisions. 
The greater the number of such elements active in the present 



THE SELF 443 

and temporary self the more do his actions spring from his 
total self, and the more do they represent his will. 

Sleep and the Self. — If the self that we know is merely 
a series of overlapping conscious states, or even a system of 
conscious contents, how can we explain the fact that after the 
interruption of sleep the self takes up the threads of experi- 
ence just where they were broken off? If we assume the 
existence of an ego, or subject self, the interruption of sleep 
offers no very difficult problem. We may then suppose that 
the ego joins the broken ends together and allows the self- 
content to go on in a continuous stream. If, on the other 
hand, we hold to the empirical point of view, we must explain 
the continuity of the self in terms of content alone. We have 
then no metaphysical self to join the broken parts together. 
There is, however, some reason to believe that sleep is not 
an absolute break in the conscious content, but a state of 
reduced consciousness in which the higher synthetic processes 
only are suspended, while the bodily or organic sense-impres- 
sions and perhaps those from some of the special senses are 
registered in a lowered form of consciousness. There is some 
empirical evidence in support of this theory. The following 
facts point to the continued existence of some form of con- 
sciousness during sleep. In certain cases of ill-health we are 
often vaguely aware of organic sensations or conditions which 
pervade our sleeping moments like a wraith. Although 
asleep, the tired mother may hear every sound made by her 
sick child. Some persons are able to judge the lapse of time 
during sleep in a remarkably accurate manner, and are able 
to awaken at any moment they have appointed before going 
to sleep. How can such conditions exist, if during sleep there 
is a state of absolute unconsciousness? Locke, on the other 
hand, held that consciousness may at times wholly disap- 
pear. If this is true, we are forced to assume the existence 
of a subject self, or else attribute the bridging of the gaps 
in the self-content to physiological or brain conditions en- 
tirely. 



444 PSYCHOLOGY 

We cannot decide the question for the periods of deepest 
sleep, but in light sleep there can be no doubt of the fact 
that a kind of vague conscious awareness is still present, 
although attention is almost completely dispersed. The di- 
rective agency of higher consciousness becomes less and less 
effective as we pass into the condition of sleep, and finally the 
associative connections between presentations are so weak- 
ened that our experiences fail to be synthetized and, there- 
fore, cannot be recalled. It is Just at this point that intro- 
spective observation fails to report anything beyond the 
presence of a vague unorganized and unconnected awareness 
which defies description. As the associative connections 
weaken, the associations become more and more irrelevant, 
and the period just preceding sleep may be marked by the 
most bizarre images and intangible creations of fancy. 

Measured by the intensity of stimuli necessary to .awaken 
sleeping subjects, the depth of sleep increases rapidly during 
the first hour, and then becomes rapidly lighter during the 
next hour and remains light until waking. The physiological 
causes of sleep are supposed to be the exhaustion of the cell 
substance in the brain, and the presence of waste material, 
or fatigue products, in the blood. The blood-vessels in the 
brain are relaxed and blood-pressure is lowered during sleep. 
Likewise all the rest of the vital processes are reduced in 
activity. If the self continues to exist during sleep it is at 
best an attenuated ghost of the waking self. 

Dreams and the Self. — Dreams mark those periods during 
sleep when the synthetic and associative tendencies of con- 
sciousness reassert themselves. They never, however, com- 
pletely re-establish themselves, for it is quite evident from 
the nature of dreams that only a fragmentary part of the 
self is active in directing the course of the conscious processes. 
All kinds of strange associations are formed during dreams 
as a result of this lack of control. Many conscious tenden- 
cies which are either too trivial, subsidiary, or vague to 
occupy the full attention of waking life, together with those 



THE SELF 445 

that are consciously inhibited or suppressed for certain rea- 
sons, tend to seek expression. When the censorship of the 
waking consciousness is lowered in sleep, these tendencies 
find an outlet in dreams. Dreams may be started by external 
stimuli, but the dream consciousness may not be at all in 
keeping with the nature of the stimuh. Dreams seem to 
have little regard for things as they really are. Dreams which 
occur shortly after falling asleep are often related to the 
things which occupied the mind during the day just closing. 
It has also been said that dreams of the early morning antici- 
pate the events of the coming day as planned on the evening 
before, and that the dreams of deep sleep are representative 
of the remote past. 

It has been claimed that the rate of flow of conscious 
states is very much more rapid in dreams than it is during 
waking consciousness, but as far as the author can determine 
there is little difference in this respect between dream con- 
sciousness and flights of reproductive imagination in waking 
hours. 

The psychiatrist Freud has proposed an interesting theory 
of dreams. He believes that dreams are symbolically repre- 
sentative of our secret wishes and desires, or ideas, that are 
repressed during the waking life. When the inhibitions of 
the waking self are removed, these secret wishes and desires 
rise to the surface and find expression in our dreams. Freud 
holds that emotional experiences of youth, usually of a sexual 
nature, may be suppressed and covered up to such an extent 
that they are half forgotten. They nevertheless remain at 
the bottom of consciousness as disturbing "complexes," which 
in many cases are the cause of hysteria. These complexes 
manifest themselves in the dream-life of the patient, but since 
the dream does not afford adequate expression they remain 
beneath the surface of consciousness as obsessions of which 
he cannot rid himself until they are brought out into the full 
light of waking consciousness. Freud therefore analyzes the 
dreams of his patients for the purpose of discovering the na- 



446 PSYCHOLOGY 

ture of the "complexes." He then forces a complete expres- 
sion of the emotional experiences and relieves the mind of 
its incubus. We cannot pass upon the correctness of Freud's 
theory of dreams, but it seems reasonable that impulses and 
tendencies that have for various reasons been denied ex- 
pression in the past should attempt to find an outlet 
whenever a lapse occurs in the continuity of rational con- 
sciousness. 

Disturbances of the Self. — We have seen that the self is 
an association of different conscious elements into a relatively 
stable organization characterized by unity and identity of 
experience. Althou,gh the contents of the self are constantly 
changing, there is in the normal self no fundamental break 
in its continuity. There is always some associative link be- 
tween the different self-contents. 

Now, while this statement is true in the main, it is not 
absolutely true, even of the normal self. The different parts 
of the self are not always bound together into a single stream 
of consciousness. It often happens that different mental 
processes take place independently of each other, and yet 
they may be carried on at the same time. For instance, a 
skilful musician may carry on an animated conversation with 
one of his auditors and at the same time play a difficult 
selection on the piano. His consciousness is divided into 
two parts, which are independent of each other. His musical 
consciousness is split off from the rest of his consciousness 
engaged at the time in conversation. He may be unaware 
for brief periods of his musical consciousness, which may in 
the meantime lead him from the particular selection he is 
playing to an entirely different selection. This splitting of 
consciousness into independent fragments, or the breaking 
down of the unity of the self is technically known as "dis- 
sociation." In the normal self, however, dissociation of con- 
sciousness is only temporary and partial, and the momentarily 
severed parts are later brought together, thus preserving the 
unity of the self. In abnormal cases, the power of bringing 



THE SELF 447 

the dissociated parts together is lost. There are many forms 
of dissociations of consciousness which may be considered as 
disturbances of the self. We will consider very briefly some 
of these dissociations of consciousness under the headings of 
''mental blindness," "automatic writing," "somnambulism," 
"hypnosis," "multiple personality," and "insanity." 

Mental or Psychic Blindness. — ^Certain cases of dissocia- 
tion manifest themselves in mental blindness or the inability 
to recognize ordinary objects when plainly seen. This condi- 
tion is caused by disintegration of the associative connections 
set up by the different past experiences of the objects. Anal- 
ogous to this condition is the inability to recognize and inter- 
pret sounds (mental deafness). While a lesion in the brain 
involving the associational pathways may furnish a structur-al 
basis for the dissociations, it may be brought about function- 
ally by suggestion in hypnotized subjects or in hysterical 
persons. The hypnotized subject can be made mentally blind 
to a certain object in the room through the suggestion of the 
hypnotist. If asked then to name the objects in the room, he 
will call off each one, excepting the one involved in the sug- 
gestion. The consciousness of that object is split off from 
the rest of his experience and fails to connect with it. It does 
not, therefore, make any impression upon him at the time. 
A hysterical patient may also become mentally blind to cer- 
tain objects or he may manifest various forms of sensory 
anaesthesia. A certain part, or all, of his skin surface may 
become apparently insensitive to all forms of stimulation. 
Anassthetic patches were in earlier times called "devil's claw" 
and were supposed to be the mark of a witch. In such cases 
of "hysterical anaesthesia" the weakened nervous condition 
makes it possible for certain experiences to slip away from 
the unifying process of the self, although they are really pre- 
sented. In a perfectly normal individual these sensory ex- 
periences are always integrated into the self. 

In these functional cases we are probably not dealing with 
absolute lack of awareness of the sensations, but with mental 



448 PSYCHOLOGY 

experiences which are split off or dissociated from the rest of 
consciousness, and which still exist in a subconscious form. 
Sometimes it is possible to tap this secondary consciousness 
and prove its existence. It is quite likely that the supposed 
unconsciousness in hysteria is not unconsciousness but a form 
of dissociated consciousness which fails to connect up with 
the rest of consciousness. 

Automatic Writing. — The phenomenon of automatic writ- 
ing, sometimes met with in normal individuals, but more 
often in cases of hysteria, also points to the existence of men- 
tal states which are dissociated from the self. If, while a 
hysterical patient is deeply interested in reading, or engaged 
in an animated conversation, or his attention held in some 
other way, a pencil is placed in his hand, he will often begin 
writing. If questions are whispered into his ear, he may be 
induced to write answers to these questions while his atten- 
tion is wholly absorbed in the reading. He is entirely uncon- 
scious of what his hand is writing, although what he writes 
may relate to certain parts of his past experiences. Not 
only is the stream of his consciousness divided into two inde- 
pendent parts, one engaged in reading and the other in writ- 
ing, but the writing consciousness is formulating ideas con- 
cerning a part of past experience which has been previously 
dissociated from the self. The two streams of consciousness 
are ignorant of each other's existence. The self is tempo- 
rarily dissociated into two systems of consciousness, each 
engaged in two different and independent activities, and in- 
volving two separate sets of memories. While such dissocia- 
tions are not different in nature from the ordinary dissocia- 
tions found in a normal self, they differ in the fact that the 
isolated fragments of consciousness remain separate contents 
of the self, and are not unified as in the c^se of the normal 
self. In fact, the presence of buried memories of certain past 
experiences in the subconscious mental life is now considered 
as the cause of hysteria. Although these memories are not 
resuscitated and brought to the surface, they nevertheless 



THE SELF 449 

remain active as subconscious and suppressed tendencies, or 
"complexes," which are constantly seeking the expression 
which is denied them. They exist only as abnormal distur- 
bances of the self. If by any means the physician is able to 
bring these suppressed complexes to the surface of the pa- 
tient's consciousness and cause him to give full expression to 
them and thereby unite the broken parts of the self, the 
sjrmptoms of hysteria disappear. It is for this purpose that 
the methods of psychoanalysis are employed. By skilful 
questioning and probing through association experiments or 
even through h3qDnosis, the patient may be led to open up 
the disturbing complexes. 

Somnambulism. — While the term somnambulism is popu- 
larly applied to sleep-walking, it includes various forms oi 
dissociated mental states in which the stream of conscious- 
ness, instead of being split into two separate streams, both 
going on at the same time, as in automatic writing, is broken 
off abruptly and is replaced by an entirely different set of 
mental states, of which the self has no knowledge. These 
dissociated mental states are entirely severed from the normal 
self. The somnambulist may, while asleep, answer questions, 
carry on a conversation, get up and hide a certain article in 
the room, or even write down the solution of a mathematical 
problem, and yet when he awakens be totally ignorant of 
what he has done. The somnambulistic states are, however, 
connected with each other. This fact is illustrated by the 
case known to the author of the boy who found in a somnam- 
bulistic state a favorite toy that he had hidden while in a 
previous similar state. In his waking condition between the 
somnambulisms he could not find the toy and had no knowl- 
edge of hiding it. 

These milder forms of dissociations during sleep may 
occur in highly nervous but otherwise normal persons. In 
hysterical persons somnambulism may take place sponta- 
neously during waking hours. The trance of the medium, 
the ecstatic state of the religious fanatic are usually somnam- 



450 PSYCHOLOGY 

bulistic states which are completely dissociated from the 
normal self. 

The case of "Irene," reported by Janet, is a form of som- 
nambulism belonging to the border-land between sanity and 
insanity. Following a prolonged and extremely painful ex- 
perience connected with the death of her mother, Irene began 
to show symptoms of a mental breakdown. Suddenly while 
engaged in her daily duties she would stop short and begin 
to live through the scenes of her mother's death. During 
these seizures she appeared to be unconscious of what was 
going on about her. She did not hear or see those who spoke 
to her. She was oblivious of everything but her former 
experiences, which she was reliving at the time. The som- 
nambulism would end as abruptly as it began, and the patient 
would take up whatever she had been doing where she left 
off, apparently unaware of the interruption. In a few days 
the same scenes would be re-enacted. Janet found that dur- 
ing her normal intervals Irene could not recall any of the 
events connected with her mother's death. These experiences 
had become completely submerged in her mind. She talked 
about her mother without emotion and manifested a surpris- 
ing indifference toward the subject of her sickness and death. 
In this case we see*' a complete dissociation from the normal 
self of a whole group of experiences. These experiences could 
not be brought to the surface of consciousness, and yet they 
were present as an isolated system of ideas in her subconscious 
life. We shall find a similar dissociation of the self in hyp- 
notic states and also in cases of double personality. When 
the dissociated system of ideas comes to the surface and takes 
the place of the normal consciousness for any length of time, 
this system forms the basis for the development of a second 
personality separate and apart from the normal personality. 

Hypnosis. — ^Hypnosis is an aberration of the self, induced 
by suggestion, in which the content of consciousness is nar- 
rowed down to the suggestions of the operator or hypnotist. 
To these suggestions the subject is abnormally sensitive. In 



THE SELF 451 

the hypnotic state the mind of the subject is impervious to 
everything except the thoughts induced by the hypnotist. 
The self-initiative of the subject is temporarily in abeyance, 
and no inhibitory ideas arise. Consequently the subject be- 
lieves everything that the hypnotist tells him and carries out 
his requests mechanically. If told that in the middle of the 
room there is a tree filled with ripe cherries, he will pick and 
eat them as though they were real. He will stand on his 
head, swim in an imaginary pool, or fight imaginary hornets, 
or execute other trivial acts in accordance with suggestions, 
or, if the intimation is given that he cannot move his arms, 
he finds himself unable to do so. In some subjects a rigid or 
cataleptic condition of the muscles may be induced by sug- 
gestion. 

The first stages of hypnosis resemble sleep. Then follows 
a stage similar to somnambulism, or sleep-walking, in which 
every idea put into the mind is carried out automatically. 
When the subject regains normal consciousness, he has no 
recollection of what happened during the state of hypnosis. 
There is a complete dissociation between the normal self and 
the self of hypnosis. 

During hypnosis there may be marked changes in the 
acuteness of the senses. Both hyperaesthesias and anaesthe- 
sias may take place under the influence of suggestions. The 
hypnotized person is very sensitive to all forms of sensory 
stimuli coming from the hypnotist with whom he is "en rap- 
port." On the other hand, certain sensory experiences may 
be banished from consciousness through suggestion. It is be- 
cause of this fact that hypnotism has been employed to a 
limited degree in certain minor operations instead of the usual 
anaesthetics. Its use in surgery has not been wide-spread 
because of the difficulty of control. The therapeutic value of 
hypnosis has bean recognized by a few medical men, but even 
here its use is very much restricted, although milder forms 
of suggestion are very widely and successfully used by physi- 
cians. 



452 PSYCHOLOGY 

The power of inducing hypnosis is not a mysterious or 
occult gift. It consists merely in the ability to attract and 
hold the attention of the subject and to give suggestions in 
a convincing manner. Hypnotic suggestions are not trans- 
mitted to the subject through any unusual channels, but, like 
all other suggestions from without, they pass through the 
ordinary sense pathways. The earlier theory that magnetic 
emanations of some kind are given off by the h3^notist is 
now discredited. 

No normal person can be hypnotized for the first time 
against his will. By refusing to accept the first suggestions 
offered, one may keep alive his normal mental resistance to 
suggestions. In order to pass into the state of hypnosis the 
subject must voluntarily give all his attention and follow the 
direction of the operator. Anything that weakens the inter- 
nal resistance of the self — fatigue, drowsiness, relaxed mental 
tone, lack of self-confidence, confidence in the operator — will 
aid in bringing about hypnosis. 

There is a marked difference among individuals in normal 
suggestibility. Some take suggestions easily, being perfectly 
willing to follow the lead of others and allow them to assume 
responsibility for whatever is done. Others are not subject 
to the domination of ideas that they themselves have not 
passed upon. Whether the difference in the ease with which 
different individuals take hypnotic suggestion coincides with 
this difference in ordinary suggestibility we are not at present 
able to determine. 

Posthypnotic suggestions are suggestions given during h)^- 
nosis, to be carried out after the subject has regained nor- 
mal consciousness. In many cases these suggestions are suc- 
cessful. The individual does not remember the nature of the 
suggestion, but at the time appointed he feels impelled with- 
out knowing why to perform the suggested act. What really 
happens is that there is a recurrence of the hypnotic condition 
and the deferred suggestion is carried out under its influence. 

Hypnotic sleep may be induced in various ways: By 



THE SELF 453 

placing the subject in a relaxed and comfortable position and 
reiterating again and again the suggestion that he feels drow- 
siness creeping over him, that he will fall asleep, one may in 
many cases bring about the condition. Or the same effect 
may be produced by requiring the subject to fixate a bright 
object or a set of rotating mirrors, or by exposing him to a 
sudden flash of light or unexpected sound, or by allowing 
him to listen to very soft and monotonous music until the 
attention is dispersed sufficiently for suggestions to take effect 
easily. Some operators stroke the forehead or pass the hands 
in front of the subject's face while suggesting sleep. 

There has been much discussion as to whether hypnosis 
is a pathological condition or an exaggerated form of ordinary 
suggestion. The modern tendency is to consider it as. an 
extreme form of suggestion, to which the self as a whole is 
unable to offer any opposition because of its temporary dis- 
sociation. In ordinary suggestion the associational and di- 
rective tendencies of the self are intact, i. e., the will is in 
command, but in hypnosis they are not effective. The nor- 
mal interplay of motives is inhibited and the power of mental 
resistance broken. 

Double Personality. — In cases of somnambulism, the dis- 
sociated systems of ideas are relatively simple, limited in 
scope, and remain on the surface of consciousness only for 
brief intervals. Usually, too, the adaptive reactions of the 
patient are crippled or entirely absent, as in trance states. 
In some cases, however, the dissociated system of conscious 
states becomes extended and comes to the surface for long 
periods of time, thus displacing the normal self. While the 
patient forgets all his past experiences, his name, his family 
and his friends, he may be able, nevertheless, to adjust him- 
self sufficiently to his environment to travel and even to earn 
his living. The dissociated consciousness constitutes a sec- 
ond personality. After this second self has occupied the stage 
for some time the real self may return and resume command. 
The patient is then bewildered and unable to orient himself, 



454 PSYCHOLOGY 

since he has no knowledge of the things which happened dur- 
ing the reign of the secondary self. In some cases these dif- 
ferent selves may alternate, first one and then the other 
assuming control. ^ 

The following account of a representative case of double 
personality is taken from James's "Principles of Psychology," 
volume I, page 391. The subject, the Reverend Ansel 
Bourne, of Greene, Rhode Island, had been brought up to 
the trade of a carpenter, but upon being converted from 
atheism to Christianity he had become an itinerant preacher. 
Previous to the dissociation of the self, he had been subject 
to headaches and temporary fits of depression, and had had 
spells of unconsciousness lasting an hour or less. He also 
had a partially anaesthetic area on the left thigh. He was 
known in the community as a man of upright character. 

"On January 17, 1887, he drew $551 from a bank in 
Providence, with which to pay for a certain lot of land in 
Greene, paid certain bills, and got into a Pawtucket horse- 
car. This is the last incident which he remembers. He did 
not return home that day, and nothing was heard of him for 
two months. He was published in the papers as missing, 
and foul play being suspected, the police sought in vain his 
whereabouts. On the morning of March 14, however, at 
Norristown, Pennsylvania, a man calling himself A. J. Brown, 
who had rented a small shop six weeks previously, stocked it 
with stationery, confectionery, fruit, and small articles, and 
carried on his quiet trade without seeming to any one un- 
natural or eccentric, woke up in a fright and called in the 
people of the house to tell him where he was. He said that 
his name was Ansel Bourne, that he was entirely ignorant 
of Norristown, that he knew nothing of shopkeeping, and 



' For accounts of alternating personalities see James's "Principles of Psy- 
chology," vol. I, pp. 379-393. The case of Sally Beauchamp, now quite well 
known to American readers, is described in "The Dissociation of a Personality," 
by Morton Prince. Boris Sidis gives a very interesting case in his book, "Mul- 
tiple Personality." 



THE SELF 455 

that the last thing he remembered — it seemed only yesterday 
— was drawing the money from the bank, etc., in Providence. 
He would not believe that two months had elapsed. The 
people of the house thought him insane, and so at first did 
Dr. Louis H. Read, whom they called in to see him. But on 
telegraphing to Providence confirmatory messages came, and 
presently his nephew, Mr. Andrew Harris, arrived on the 
scene, made everything straight, and took him home." 

It should be remembered that double personality mani- 
fests itself only in persons already possessing unstable patho- 
logical tendencies. 

Insanity. — In early times insanity was considered a mani- 
festation of some supernatural agency, and the insane were 
either revered as holy, or looked upon as victims of some evil 
spirit. Hippocrates, the father of medicine, was among the 
first to oppose this superstition. He beheved that the brain 
was the organ of the mind and, therefore, that mental dis- 
turbances were due to abnormal conditions in the nervous 
system. In modern times this physiological conception of 
insanity has become the prevailing one. We have come to 
beUeve that disorders of the mind are based upon disturbed 
brain functions. While in many cases we are able to point 
out the definite brain conditions which produce insanity, 
there are other cases in which we are unable, as yet, to dis- 
cover aiiy structural defects of the brain. This has led to a 
general classification of insanities into structural and func- 
tional. The functional insanities are those which reveal no 
demonstrable abnormality of the brain. It 'is thought by 
some that they are due to purely psychical disturbances of 
the mind, while others believe that further knowledge will 
enable us to find a physiological basis for them as well. 

Even though we may accept the physiological conception 
of insanity, we can nevertheless take the purely psychological 
point of view in the study of these abnormal mental phenom- 
ena. If we take the psychological point of view we may ab- 
stract from the brain conditions which cause insanity and 



456 PSYCHOLOGY 

confine ourselves to a description of the mental changes and 
conditions which insanity exhibits. The psychological con- 
ception, then, looks upon the phenomena only as states of 
mind, and does not attempt to go beyond the realm of mental 
facts. 

The actual cases of insanity exist in so many varied forms 
that the task of classifying them is a very difficult one. We 
may, however, without going into the matter very deeply, 
call attention to the most prominent characteristics which 
differentiate the disturbances of the self. Insanity may be 
defined as a change or disturbance of the self which renders 
it incapable of functioning in a normal way. These changes 
may affect the self as a whole, or they may affect only a sin- 
gle part or function of the self. The former mental defect is 
a quantitative change consisting in a lessening of the general 
mental capacity of the individual. He loses his ability to 
think and act efficiently, his intelligence degenerates and he 
becomes a being of low and enfeebled mentality. This con- 
dition is known as dementia. Its character is best illustrated 
in the decay or weakening of the mind which accompanies 
extreme old age, when it is spoken of as senile dementia. 
Dementia, however, may occur at any age, and may mani- 
fest itself in various degrees of loss of intelligence, from a 
slight lowering of mental power to an almost complete loss of 
mentality. Dementia is acquired. The patients have been 
at one time persons of normal mental capacity but mental 
decay has destroyed their powers. 

Besides these acquired forms of weak mentality, there are 
other forms which are not acquired, but congenital. They 
are known Sisfeeble-mindedness, and are not usually considered 
among the insanities. The feeble-minded are born with a 
weak mentality and never attain a normal mental develop- 
ment. They are sometimes referred to as cases of arrested 
mental development. Feeble-mindedness may exist in all 
degrees, ranging from the lowest grade of mentality to a 
condition which is only slightly below normal. It has be- 



THE SELF 457 

come customary to group the feeble-minded into three classes 
— idiots, imbeciles, and morons. The idiot possesses only the 
lowest level of intelligence. He never reaches the plane of 
spoken language and is, therefore, incapable of speech. He 
can understand and use simple gestures, but he is unable to 
care for himself. He requires the same kind of oversight 
that is given to a very young child. His mentality does not 
exceed that of a child of two years. 

The imbecile possesses a slightly higher degree of intelli- 
gence. He is capable of understanding spoken language and 
learns to talk himself, although he is incapable of learning to 
read and write efficiently. His knowledge remains in a very 
elementary stage and never reaches the plane of general ideas. 
His mental development corresponds to that of children from 
two to eight years of age. 

The moron represents a still higher degree of mental de- 
velopment. In addition to the acquisition of spoken lan- 
guage he is capable of learning to read and write, and in 
many cases is able to earn a living in the simplest forms of 
labor. His mentality corresponds to that of children from 
eight to twelve years of age. The mental inferiority of the 
idiot, the imbecile, and the moron is in most cases congenital, 
and is due to a defective heredity. The offspring of weak- 
minded individuals are as a rule weak-minded, also. In some 
cases mental inferiority is due to a pathological taint in the 
parents who are otherwise normal. In a few cases it is the 
direct result of such organic diseases as meningitis and scarlet 
fever. 

While dementia and weak-mindedness are both quantita- 
tive defects of the mind as a whole, there are other alterations 
of the self which may be regarded as quahtative in nature. 
These qualitative changes are often temporary in character, 
although in some cases they are more or less permanent. 
With a few exceptions they are regarded as recoverable kinds 
of insanity. These cases are marked by the general psychic 
attitude which the subject takes toward his experience. 



458 PSYCHOLOGY 

Three of the most common attitudes are those of excitement 
depression, and indifference. 

Mania is the most common form of mental excitement. 
The maniac exhibits an abnormal excitability, shown in vio- 
lent motor activity and rapid flights of ideas. He talks rap- 
idly and constantly, jumping from one idea to another with- 
out logical connection. He does not carry out any connected 
train of thought. His movements are erratic and constant. 
He occupies himself first with one thing and then with an- 
other, beginning a new task every few minutes. His atten- 
tion is easily diverted from whatever he is doing. The ma- 
niac is usually in a state of emotional excitement. Generally 
he is abnormally pleased with himself and everything about 
him, although his emotional tone may change to that of irri- 
tability or violent anger at the sKghtest provocation. In 
some extreme forms the emotional excitement reaches the 
highest pitch. The patient becomes unmanageable and at- 
tacks those about him. 

Melancholia represents the opposite psychic attitude of 
depression. Here the patient is abnormally slow in thought 
and speech. He sinks into a state of deep misery and unhap- 
piness, from which nothing is able to raise him. He con- 
tinually broods over his real or fancied misfortunes. 

Dementia pracox manifests the psychic attitude of indif- 
ference. The patient lacks interest in the things about him. 
He pays no attention to the things which the normal person 
is keenly ahve to. He has no hopes, or plans, or ambition, 
and is content to remain in his present condition. He is un- 
tidy and slovenly in his dress and habits. There is a loss of 
personal modesty due to the lack of a proper emotional atti- 
tude. The stream of thought is shallow and weak, and con- 
versation is incoherent and unintelligible. This form of men- 
tal aberration appears in the young usually about the age of 
puberty, and is progressive. Absolute indifference or apathy 
is also manifest in apparent or emotional dementia. In these 
cases the patient really possesses mental capacity, but be- 



THE SELF 459 

cause of his abnormal emotional indifference he does not use 
it in any way. He sits in one position for long periods of 
time, motionless and inert, making no effort whatever, even 
to answer simple questions addressed to him. He shows no 
interest in the happenings that take place around him. It 
is impossible to arouse him from his mental lethargy. 

There are other forms of insanity which involve distur- 
bances on the intellectual side of the self. While emotional 
changes accompany these intellectual aberrations, they are 
secondary — not primary, as in the preceding cases. Paranoia, 
for instance, is primarily an abnormality of the intellect. A 
patient who apparently is normal in other respects may be- 
come the victim of some delusional idea, or may be subjected 
to hallucinations which he is unable to distinguish from th« 
reality about him. A false idea may spring up in his mind 
which he is unable to correct. He may believe that his arms 
are made of glass or that some person is persecuting him by 
trying to poison him. For this reason he may refuse to take 
food. He thinks he hears threatening and insulting voices 
which he takes to be real, although in other things he seems 
perfectly rational. As a result of these delusional and hallu- 
cinatory ideas the patient loses his mental equilibrium and 
begins to act strangely. On the other hand, the patient may 
develop "delusions of grandeur." He entertains an exag- 
gerated idea of his own importance and frequently looks upon 
himself as some celebrated character, a millionaire, great in- 
ventor, King, or savior of the world, without realizing the 
discrepancies between his real and his fancied condition. 
Frequently delusions of persecution and delusions of grandeur 
are combined. The patient may think himself a great in- 
ventor, but that certain persons are stealing his inventions 
and conspiring to deprive him of proper and rightful recogni- 
tion by the world. 

Thus we see that hallucinations and delusions play an im- 
portant and varied part in the insanities involving the dis- 
turbances of the intellectual side of the self. Hallucinations 



46o PSYCHOLOGY 

are false perceptions, through which the patient becomes 
aware of objects having no real existence. Auditory hallu- 
cinations are very frequent among the insane. Some patients 
are repeatedly hearing voices which threaten or reproach 
them. Since these are believed real, they become serious dis- 
turbances of the self. 

While hallucinations are false perceptions, delusions are 
false beliefs. Thus, if a patient sees, or hears, or in any way 
senses an object which has no objective existence, he has a 
hallucination, but if he believes that he is the Emperor of 
China, or that everybody is trying to put poison in his food, 
he has a delusion. A delusion may become the basis for an 
entirely new system of view-points and reactions. Everything 
is changed and distorted to agree with the delusional belief. 
An important characteristic of a delusion is its perseverance. 
No argument is able to dispel it. The most convincing proof 
of its falsity is of no avail. 

Obsessions comprise another form of intellectual abnor- 
mality, which, although in a way similar to delusions, are to 
be distinguished from them. Delusions carry with them the 
belief in their reality, while obsessions do not. An obsession 
is the persistent presence of an idea, or other psychic element 
in consciousness, in spite of all efforts to banish it. A very 
frequent obsession is the so-called "washing mania," in which 
the patient feels that his hands are soiled and must be washed. 
He knows that they are not soiled, but he is impelled in order 
to rid himself of the idea to wash his hands every few minutes 
during his waking hours. He is not deluded intellectually, 
i. e., he does not believe that his hands are dirty, but he can- 
not get the insistent idea out of his mind. Obsessions exist 
in various forms, from the impulsion to count every crack in 
the sidewalk to the insistent idea of killing one's own mother. 
Obsessions are found most frequently in those cases of ner- 
vous debility (neurasthenia) which lie on the border-land be- 
tween sanity and insanity. In some cases the overweighting 
of an idea may be so persistent and pronounced as to over- 



THE SELF 461 

balance the rational structure of the self and produce in- 
sanity. 

Hysteria is also a form of self-alteration which can hardly 
be classed among the insanities, and yet, at times, it ap- 
proaches very near if it does not reach the stage of insanity. 
It shows itself in a highly exaggerated impressionability and 
suggestibility, in undue attention given to the self, and in an 
abnormal desire for sympathy. It also exhibits marked dis- 
turbances of sensations and of motor and glandular activities. 
Loss of sensations (anaesthesia) may appear in certain areas, 
sometimes to such an extent that needles may be thrust into 
the skin without causing pain. The areas may vary in size 
from a small patch to that of the whole skin. In some cases 
there may be a heightened sensibility (hyperassthesia) and in 
some a distorted or perverted sensibility (parsesthesia) . The 
fact that an exaggerated suggestibility is a marked charac- 
teristic of hysteria has led to the belief that it is due to sub- 
conscious states of mind not unlike those found in the hyp- 
notic state. This seems all the more probable since patients 
are often cured merely by suggestion. While there is a dif- 
ference of opinion, some authorities look upon hysteria as a 
functional disturbance depending upon subconscious ele- 
ments. The mental conditions which are held to be funda- 
mental are disguised by the facts that hysterical patients 
simulate the effects of various organic diseases. The appear- 
ance of such organic disturbances without any structural 
defects has made hysteria a very difficult condition to under- 
stand. 

Freud and others believe that hysteria is due to definite 
emotional shocks which, although forgotten or suppressed, 
and dissociated from the conscious self, still play a disturbing 
subconscious part in the mental life of the self. Such subcon- 
scious states are termed "complexes." Embedded and held 
in the depths of the self, they are thought to be the cause of 
vague, foreboding fears and doubts which often mark the 
beginning of mental alienation. The method of treatment 



462 PSYCHOLOGY 

(psychoanalysis) consists in reviving the forgotten or sup- 
pressed experiences (complexes) which were the cause of the 
emotional shocks and in subjecting them to careful and ra- 
tional consideration by the patient. When this is done, the 
dissociated fragments of experience are regained and given 
their proper value among the other elements of the self. The 
subject is then relieved of the disturbing influences and re- 
gains control of his mental processes and the bodily symp- 
toms of organic disturbances accompanying the hysteria dis- 
appear. 

Besides the so-called functional disorders which we have 
just discussed, there are a number of mental disorders usually 
placed under the head of structural psychoses. Among them 
are to be noted general paresis, or softening of the brain, 
choreic psychoses, epileptic psychoses, and toxic psychoses, all of 
which are due to definite structural defects of the brain and 
nervous system. Many of the psychic disturbances already 
described also appear in the structural insanities and need 
no further elaboration in this brief account of insanity. 

From the foregoing description of the different distur- 
bances of the self it is evident that they owe their character 
to a lack of harmony among the elements of the self. Some 
of the mental processes may become overexaggerated and 
overbalance the self-structure. The disturbances may mani- 
fest themselves on the emotional, the volitional, or on the in- 
tellectual side of the self. Accordingly, we find the melan- 
cholias and emotional insanities, obsessions, and delusions. 
Conflicts between different systems of experience within the 
self may result in dissociations and the formation of com- 
plexes which tend to change the relations between the parts 
of the self and destroy its unity. 



BIBLIOGRAPHY 

The books and articles on psychology written since 1894 are in- 
dexed in the annual Psychological Index of the Psychological Review. 
An extended bibliography of works on psychology can be found in 
Baldwin's "Dictionary of Philosophy and Psychology," published in 
1 901. 

GENERAL PSYCHOLOGY 

Angell, J. R. "Psychology." 1905. 

"Chapters from Modern Psychology." 191 2. 

Baldwin, J. Mark. "The Story of the Mind." 1898. 

"Dictionary of Philosophy and Psychology." 3 vols. 1901- 

1905. 
Calkins, Mary W. "A First Book in Psychology." 1910. 
Dunlap, Knight. "A System of Psychology." 191 2. 
Ebbinghaus, Hermann. "Psychology, an Elementary Text-Book." 

(Tr.) 1908. 
Hoffding, Harald. "Outlines of Psychology." (Tr.) 1891. 
James, William. "The Principles of Psychology." 2 vols. 1890. 

"Psychology — Briefer Course." 1893. 

Judd, C. H. "Psychology, General Introduction." 1907. 

Kiilpe, Oswald. "Outlines of Psychology." (Tr.) 1895. 

Ladd, George T. "Psychology, Descriptive and Explanatory." 1894. 

McDougall, William. "Psychology, the Study of Behavior." 191 2. 

Miinsterberg, Hugo. "Psychology, General and Applied." 1914. 

Ogden, R. M. "An Introduction to General Psychology." 1914. 

Pillsbury, W. B. "The Fundamentals of Psychology." 1916. 

Royce, Josiah. "Outlines of Psychology." 1903. 

Spencer, Herbert. "Principles of Psychology." 2 vols. 1895. 

Stout, G. F. "A Manual of Psychology." 1899. 

"The Groundwork of Psychology." 1903. 

"Analytic Psychology." 2 vols. 1896. 

Sully, James. "Handbook of Psychology." 1909. 

Thorndike, E. L. "The Elements of Psychology." 1906. 

Titchener, E. B. "A Text-Book of Psychology." 191 1. 

Ward, James. "Psychology." Article in Encyclopaedia Britannica. 

1911. 

463 



464 BIBLIOGRAPHY 

Wundt, Wilhelm. "Outlines of Psychology." (Tr.) 1902. 

"Human and Animal Psychology." (Tr.) 1894. 

Yerkes, R. M. "Introduction to Psychology." 191 1. 

ATTENTION 

Arnold, Felix. "Attention and Interest." 1910. 

Pillsbury, W. B. "Attention." 1908. 

Ribot, Th. "The Psychology of Attention." (Tr.) 1899. 

Titchener, E. B. "Psychology of Feeling and Attention." 1908. 

REASONING 

Binet, Alfred. "Psychology of Reasoning." (Tr.) 1899. 
Dewey, John. "How We Think." 1910. 
Miller, I. E. "The Psychology of Thinking." 1909. 
Pillsbury, W. B. "The Psychology of Reasoning." 19 10. 

EXPERIMENTAL PSYCHOLOGY 

Judd, C. H. "Laboratory Equipment for , Psychological Experi- 
ments." 1907. 

■ "Laboratory Manual of Psychology." 1907. 

Langfeld and AUport. "An Elementary Laboratory Course in Psy- 
chology." 1916. 

Myers, Charles S. "A Text-Book of Experimental Psychology." 
1911. 

Sanford, E. C. "A Course in Experimental Psychology." 1898. 

Seashore, C. E. "Elementary Experiments in Psychology." 1908. 

Stratton, G. M. "Experimental Psychology and Its Bearing upon 
Culture." 1903. 

Titchener, E. B. "Experimental Psychology." Four Parts. 1901- 
1905. 

"Experimental Psychology of the Thought Processes." 1909. 

Witmer, Lightner. "Analytical Psychology." 1902. 

PHYSIOLOGICAL PSYCHOLOGY 

Donaldson, H. H. "The Growth of the Brain." 1900. 

Dunlap, Knight. "An Outline of Psychobiology." 1914. 

Edinger, Ludwig. "The Anatomy of the Central Nervous System of 

Man." (Tr.) 1899. 
Herrick, C. J. "Introduction to Neurology." 1915. 
Ladd and Woodworth. "The Elements of Physiological Psychology." 

1911. 
Lickley, J. D. "The Nervous System." 191 2. 



BIBLIOGRAPHY 465; 

Loeb, Jacques. "Comparative Physiology of the Brain and Com- 
parative Psychology." 1900. 

McDougall, William. "Primer of Physiological Psychology." 1905. 

M'Kendrick and Snodgrass. "The Physiology of the Senses." 1893. 

Sherrington, C. S. "The Integrative Action of the Nervous System." 
1906. 

Stiles, P. G. "The Nervous System and Its Conservation." 1914. 

ViUiger, Emil. "Brain and Spinal Cord." (Tr.) 191 2. 

Wundt, Wilhelm. " Principles of Physiological Psychology." (Vol.1, 
Tr.) 1910. 

Ziehen, T. "Introduction to the Study of Physiological Psychology." 
(Tr.) 1895. 

SOCIAL PSYCHOLOGY 

Anderson, B. M. "Social Value." 191 1. 

Baldwin, J. Mark. "Social and Ethical Interpretations in Mental 

Development." 1897. 

"The Individual and Society." 191 1. 

Boas, Franz. "The Mind of Primitive Man." 191 1. 
Brinton, D. G. "The Basis of Social Relations." 1902. 
Cooley, C. H. "Human Nature and the Social Order." 1902. 
Ellis, Havelock. "Studies in the Psychology of Sex." 6 vols. 1900- 

1910. 
Ellwood, C. A. "Sociology in Its Psychological Aspects." 191 2. 
Gross, Hans. "Criminal Psychology." (Tr.) 1911. 
Le Bon, Gustave. "Psychology of Peoples." (Tr.) 1898. 

"The Crowd." (Tr.) 1896. 

— — "The Psychology of Revolution." (Tr.) 1913. 

McDougaU, Wilham. "An Introduction to Social Psychology." 1908. 

Ross, E. A. "Social Psychology." 1908. 

Shand, A. F. "The Foundations of Character." 1914. 

Spencer, Herbert. "Descriptive Sociology." 1873-1881. 

Tarde, Gabriel. "The Laws of Imitation." (Tr.) 1903. 

Thomas, William I. "Source Book for Social Origins." 1909. 

"Sex and Society." 1907. 

Tylor, E. B. "Primitive Culture." 1871. 

Wallas, Graham. "The Great Society, a Psychological Analysis." 

1914. 

"Human Nature in Politics." 1908. 

Ward, Lester F. "The Psychic Factors of Civilization." 1893. 
Wundt, Wilhelm. "Elements of Folk Psychology." (Tr.) 1916. 



466 BIBLIOGRAPHY 



EDUCATIONAL PSYCHOLOGY 

Bagley, William C. "The Educative Process." 1910. 
\ Colvin and Bagley. "Human Behavior." 1914. 
T^sColvin, S. S. "The Learning Process." 191 2. 

Freeman, F. N. "The Psychology of the Common Branches." 1916, 

"Experimental Education." 1916. 

Home, H. H. "The Psychological Principles of Education." 1908. 

James, William. "Talks to Teachers." 1908. 

Judd, C. H. "Psychology of High-School Subjects." 1915. 

"Genetic Psychology for Teachers." 1909. 

Lee, Joseph. "Play in Education." 1916. 

Meumann, E. "Psychology of Learning." (Tr.) 1913. 

Miinsterberg, Hugo. "Psychology and the Teacher." 1909. 

Offner, Max. "Mental Fatigue." (Tr.) 191 1. 

Pyle, W. H. "Outlines of Educational Psychology." 191 1. 

Rusk, R. R. "Introduction to Experimental Education." 1912. 

Sandiford, Peter. "The Mental and Physical Life of School Chil- 
dren." 1913. 

Schulze, R. "Experimental Psychology and Pedagogy." (Tr.) 1912. 

Starch, Daniel. "Experiments in Educational Psychology." 1911. 

Thorndike, E. L. "Education." 191 2. 

— — ■ "Educational Psychology." 3 vols. 1913. 

"Educational Psychology, Briefer Course." 1915. 

CHILD PSYCHOLOGY 

Baldwin, J. Mark. "Mental Development in the Child and in the 

Race." 1895. 
Claparede, Ed. "Experimental Pedagogy and the Psychology of the 

Child." (Tr.) 191 1. 
Groos, Karl. "The Play of Man." (Tr.) 1901. 
Hall, G. Stanley. "Adolescence." Two vols. 1905. 
Kirkpatrick, E. A. "The Individual in the Making." 191 1. 

, "Fundamentals of Child Study." 1903. 

*^Major, David R. "First Steps in Mental Growth." 1906. 

Montessori, Maria. "Pedagogical Anthropology." (Tr.) 1913. 

"The Montessori Method." (Tr.) 191 2. 

Oppenheim, Nathan. "The Development of the Child." 1910. 

Preyer, W. "The Mind of the Child." (Tr.) 1890. 

Shinn, Milicent. "Notes on the Development of a Child." 2 vols. 

1893. 
Stoner, Winifred. "Natural Education." 1914. 



BIBLIOGRAPHY 467 

^*---Svilly, James. "Studies of Childhood." 1895. 

Tracy, Frederick. "The Psychology of Childhood." 1909. 

Warner, Francis. "The Nervous System of the Child." 1900. 
)C "The Study of Children." 1899. 

RELIGIOUS PSYCHOLOGY 

Ames, E. S. "The Psychology of Religious Experience." 1910. 
Coe, G. A. "The Religion of a Mature Mind." 1903. 

"The Spiritual Life." 1900. 

Davenport, F. M. "Primitive Traits in Religious Revivals." 1906. 
Durkheim, Emil. "Elementary Forms of the Religious Life." (Tr.) 

1915- 
James, William. "Varieties of Religious Experience." 1903. 
King, Irving. "The Development of Religion." 1910. 
Leuba, J. H. "A Psychological Study of Religion." 191 2. 
McComas, H. C. "The Psychology of Religious Sects." 191 2. 
Pratt, J. B. "The Psychology of Religious Belief." 1907. 
Starbuck, E. D. "The Psychology of Religion." 1901. 
Stratton, G. M. "Psychology of the Religious Life." 191 1. 

ESTHETICS 

Gordon, Kate. "Esthetics." 1909. 

Hildebrand, A. "The Problems of Form in Painting and Sculpture." 

(Tr.) 1907. 
Pufifer, Ethel. "Psychology of Beauty." 1904. 
Rowland, Eleanor. "The Significance of Art." 1913. 

ANIMAL PSYCHOLOGY 

Forel, A. "The Senses of Insects." 1908. 

Groos, Karl. "The Play of Animals." (Tr.) 1898. 

Holmes, S. J. "The Evolution of Animal Intelligence." 1911. 

"Studies in Animal Behavior." 1916. 

Jennings, H. S. "Behavior of the Lower Organisms." 1906. 
Morgan, Lloyd. "Instinct and Experience." 191 2. 

"Habit and Instinct." 1896. 

"Animal Life and Intelligence." 1891. 

"Introduction to Comparative Psychology." 1894. 

Smith, E. M. "The Investigation of Mind in Animals." 1915. 
Thorndike, E. L. "Animal Intelligence." 191 1. 
Washburn, Margaret. "The Animal Mind." 1908. 
Watson, John B. "Behavior, an Introduction to Comparative Psy- 
chology." 1914. 



468 BIBLIOGRAPHY 



ABNORMAL PSYCHOLOGY 

Barr, M. W. "Mental Defectives, Their History, Treatment, and 
Training." 1910. 

Binet and Simon. " Mentally Defective Children." (Tr.) 1914. 

Brill, A. I. "Psychoanalysis." 1913. 

Burr, C. B. "Psychology and Mental Disease." 1906. 

Dana, C. L. "Text-Book of Nervous Diseases and Psychiatry." 1904. 

Freud, Sigmund. "The Interpretation of Dreams." (Tr.) 1913. 

Goddard, H. H. " Feeble-Mindedness, Its Causes and Consequences." 
1914. 

Guthrie, L. B. "Functional Nervous Disorders in Childhood." 1907. 

Hart, Bernard. "The Psychology of Insanity." 1914. 

Holmes, Arthur. "Backward Children." 191 5. 

Janet, P. "The Major Symptoms of Hysteria." (Tr.) 1907. 

Jung, C. G. "Psycho-analysis." 1913. 

Kelynack, T. N. (Ed.) "Defective Children." 1915. 

Lapage, C. P. "Feeblemindedness in Children of School Age." 191 1. 

Miinsterberg, Hugo. "Psychotherapy." 1909. 

Quackenbos, J. D. "Hypnotic Therapeutics." 1907. 

Rachford, B. K. "Neuroses of Childhood." 1895. 

Sherlock, E. B. "The Feeble-Minded." 1911. 

Shuttleworth and Potts. "Mentally Deficient Children, Their Treat- 
ment and Training." Third Edition. 1910. 

Sidis and Goodhart. "Multiple Personality." 1905. 

Tredgold, A. F. "Mental Deficiency." 1908. 

VOCATIONAL PSYCHOLOGY 

Bloomfield, M. "Readings in Vocational Guidance." 1915. 
Gilbreth, F. S. "Motion Study." 1911. 

"Psychology of Management." 1914. 

Goldmark, Josephine. "Fatigue and Efficiency." 1912, 
Gowin, E. B. "The Executive and His Control of Men." 1915. 
Hollingworth, H. L. "Vocational Psychology." 1916. 
Miinsterberg, Hugo. "Psychology and Industrial Efficiency." 19 13. 

"Business Psychology." 191 5. 

Scott, Walter Dill. "Increasing Human Efficiency in Business." 191 1. 

"Influencing Men in Business, the Psychology of Argument and 

Suggestion." 191 1. 
Taylor, F. W. "The Principles of Scientific Management." 191 1. 



BIBLIOGRAPHY 469 



ADVERTISING 

Adams, H. F. "Advertising and Its Mental Laws." 1916. 
HoUingworth, H. L. "Advertising and Selling." 1913. 
Scott, Walter Dill. "The Theory of Advertising." 1903. 
-^ — "The Psychology of Advertising." 1908. 

HYPNOTISM 

Binet, Alfred. "Alterations of Personality." (Tr.) 1903. 

Bramwell, J. M. "Hypnotism." 1906. 

Moll, Albert. "Hypnotism." 1899. 

Prince, Morton. "The Dissociation of a Personality." 1906. 

Sidis, Boris. "The Psychology of Suggestion." 1901. 

Wetterstrand, Otto. "Hypnotism." (Tr.) 1902. 

MENTAL TESTS 

Binet and Simon. "A Method of Measuring the Development of the 
Intelligence of Young Children." (Tr.) 1913. 

Franz, S. I. "Handbook of Mental Examination Methods." 1912. 

Miinsterberg, Hugo. "Psychology and Industrial Efficiency." 1913. 

Stern, William. "The Psychological Methods of Testing Intelli- 
gence." (Tr.) 1914. 

Terman, L. M. "The Measurement of Intelligence." 1916. 

Thorndike, E. L. "Mental and Social Measurements." 1904. 

Whipple, Guy M. "Manual of Mental and Physical Tests." 1914. 

Yerkes, Bridges, and Hard wick. "A Point Scale for Measuring 
Mental Ability," 1915. 

HISTORY OF PSYCHOLOGY 

Baldwin, J. M. "History of Psychology." 2 vols. 1913. 

Brett, G. S. "A History of Psychology." 1912. 

Dessoir, Max. "Outlines of the History of Psychology." (Tr.) 1912, 

Hall, G. Stanley. "Founders of Modern Psychology." 191 2. 

Klemm, Otto. "A History of Psychology." (Tr.) 1914. 

Rand, Benjamin. "The Classical Psychologists." 191 2. 

Villa, Guido. "Contemporary Psychology." (Tr.) 1903. 

MISCELLANEOUS 

Bergson, Henri. "Time and Free Will." (Tr.) 1912. 
Darwin, Charles. "The Expression of the Emotions in Man and Ani- 
mals." 1872. 
Hobhouse, L. T. "Mind in Evolution." 1901. 



470 BIBLIOGRAPHY 

Jastrow, Joseph. " Character and Temperament." 1915. 

"The Qualities of Men." 1910. 

"Fact and Fable in Psychology." 1900. 

"The Subconscious." 1906. 

McDougall, William. "Body and Mind." 191 1. 
Miinsterberg, Hugo. "Psychology and Social Sanity." 1914. 

"On the Witness Stand." 1908. 

Parmelee, M. "The Science of Human Behavior." 1913. 

Ribot, Th. "The Psychology of the Emotions." (Tr.) 1897. 

Seashore, C. E. "Psychology in Daily Life." 1914. 

Sisson, E. O. "The Essentials of Character." 1910. 

Spurzheim, J. G. "Phrenology." (Revised from Second Edition, 

published in 1833.) 1908. 
Washburn, Margaret F. " Movement and Mental Imagery." 1916. 
Watt, H. J. "The Economy and Training of Memory." 1911. 

LEADING PSYCHOLOGICAL JOURNALS IN ENGLISH 

American Journal of Psychology. 

Psychological Review. 

British Journal of Psychology. 

Mind. 

Journal of Philosophy, Psychology, and Scientific Methods, 

Psychological Bulletin. 

Archives of Psychology. 

Journal of Educational Psychology. 

Journal of Animal Behavior. 

Behavior Monographs. 

Journal of A bnormal Psychology. 

Psychological Monographs. 

Journal of Experimental Psychology. 

Journal of Religious Psychology. 

Journal of Applied Psychology. 



INDEX 



Abnormal psychology, as a field of corn 
sciousness, 3; disturbances of the self 
in, 44.6 ff.; use of association method in, 
29s /•, 449; psychoanalysis in, 295 /., 
44S ff., 461 

Absolute pitch, 156, 328 

Abstraction, in formation of concept, 
302 ff. 

Accommodation of lens, mechanism of, 
166/., 171, Fig. 57; in presbyopia, 171; 
sensation from, in perception of depth, 
221; a cause of fluctuation in percep- 
tion, 73 /. 

Accommodation of sense-organs, in atten- 
tion, 54, 73 /., 83, 169; in vision, 73 /., 
166/.; in audition, 73 /., 146 

Ach, 423 

Achromasia, 189 

Action theory of affection, 368 

Adaptation, sensory, g6 /. ; and intensity, 
99; in pain and pressure, 96, 124; in 
temperature, 127; in smell, 96, 134; in 
gustatory sensation, 141; in color and 
brightness, 184/.; in daylight and twi- 
light vision, 96/., 175, 180 

Adaptation in affection, 361, 362 

AdrenaUn secretion in emotion, 387 

/Esthetic experience, consonance and dis- 
sonance in tones, 162 ff., 358; judgment 
as evaluation in, 328/.; intellectualistic 
view of affection in, 358; feeUng in, 
373; as a sentiment or ideal, 376 

Affection, Chapter XVI, 356-376; refer- 
ence of consciousness in, 356; nature of, 
35(> ff.; as an element in consciousness, 
356/., 359; in feeling, 356, 370 ff.; and 
cognition, 356 ff., 361 ff.; in attention 
and interest, 54 /., 84 /.; and pain- 
sensation, 124, 362, 370; theories of, 
357 /•; attributes of, 360 /.; qualities 
of, 357, 359/.; tridimensional theory of, 
359/.; adaptation in, 361 /.; and sensa- 
tion, 357 f; 361, 366/.; and perception, 
363; and ideational processes, 363; and 



bodily expression, 364; in conscious- 
ness of self, 441 ; significance and func- 
tion of, 368; neural basis of, 366/., 382 

After-image, 94 /.; of pain and pressure, 
123; visual, 94/., 185/., 191, 193 

Ageusia, partial, 140 

Alcohol, effects of, in hallucinations, 211; 
on imagery, 265 

Alexia, 51, 201 

Alimentary sensations, see Organic sen- 
sations 

Amnesia, 257 

Anaesthesia, in hysteria, 447, 461; in 
hypnosis, 451 

Analogy, reasoning by, 347 

Analysis, in formation of concept, 302; in 
judgment, 333 /. 

Angell, 27, 40, 76, 83, 173. 353, 393, 428 

Anger, 384; organic sensations in, no 

Animal psychology, as a field of con- 
sciousness, 3, 6; observation of behavior 
in, 10, 381, 387, 405 /.; evolution of 
nervous system and consciousness, 22, 
354; acuity of smell, 135 /.; learning in 
animals, 405 /.; experimentation in 
emotion, 381, 387 

Anomalous color- vision, 190 

Anosmia, partial, 134 

Aphasia, motor, 51; sensory, 51 

Apperception, 199 ff.; judgment as, 322 
/., 324; see Assimilation 

Appetition, 369 

Apprehension, 330, 340 

Aristotle, 283 

Aristotle's illusion, 206 /. 

Art and imagination, 261 ff., 267; and 
feeling, 371 

Articular sensations, 104, 214, 214/.; see 
Kinsesthetic sensations 

Assimilation, in perception, 199 ff.; in 
illusions, 206 ff., 228; judgment as, 
322/., 324; and the self, 440 

Association, Chapter XII, 277-298; na- 
ture of, 243 ff., 277 ff.; formation of. 



471 



472 



INDEX 



278^.; attention and, 53, 81, 278, 282; 
as motor connections, 279; as mental 
connections, 279 ff.; in recall, 243 f., 
283 J".; laws of, 283^.; contiguity, law 
of, 284/.; similarity, law of, 285/., 350; 
partial and total recall in, 250/., 288/.; 
falsification of, 289; in judgment, 324, 
328; in reasoning, 350; in sleep and 
dreams, 444 /.; dissociation, 446 ff.; 
tests, 290^., 449; neural basis of, 49/., 
69, 242, 354 /., 283, 285, 296 f. 

Association areas in cortex, 49 /. 

Association tests, 290 f., 449 

Associationalists, 274, 277, 283 

Astigmatism, 172 

Asymbolia, 201 

Attention, Chapter III, 53-86; definition 
of, 58; nature of consciousness in, 53 
ff.; structural characteristics of, 54, 
56 /.; functional characteristics of, 57 
/.; forms of, 58 jf.; development of, 63 
/., 8s; effort in, 54, 58, 61, 66, 83; 
factors determining direction of, 53 /., 
59/-. 67, ?,s; interest and, 54/., 59/., 
84/.; shifting of, 70 J".; range or span 
of, 76/.; effort of, 78^.; motor accom- 
paniments of, 81 ^.; accommodation of 
sense-organs in, 54, 73 /., 83, 169; and 
perception, 79, 309; and association, 
5:^, 81, 278, 282; and memory, 81, 253, 
254; and concept, 308, 309; and judg- 
ment, 330; and feeling, 54/., 362; and 
will, 422, 427; and the self, 440; neural 
basis of, 67 ff., 74 /., 298 

Auditory area, 48, 152 

Auditory nerve, 30, 45 /., 152 

Auditory sensations. Chapter VII, 144- 
165; classification of, 109, 144; stimulus 
of, 152 /.; end-organ of, 144 f., 154; 
evolution of end-organ, 90; brain areas 
of, 48, 152; noises, 154; tones, 155; 
compound tones, 157; timbre, 158, 229; 
beats, 159 /., 165; combination tones, 
160; musical tones, consonance and 
dissonance, 162 ff.; intensity of, 161, 
229; Weber's law in, loi; extensity 
attribute in, 104, 161, 214 /.; localiza- 
tion and projection of, 228/.; in time 
perception, 233; and imagery, 267, 272; 
and feeling, 361; theories of, 150/., 162 

Auditory space perception, extensity at- 
tribute of auditory sensations, 103 /., 
161 /., 216; localization and projection, 
228/. 



Aufgahe,pss 

Automatic work in industry, effect of, 409 

Automatic writing, 448 

Autonomic nervous system, 31, Fig. 5 

Aversion, 369 

Awareness, see Consciousness, Attention 

Axon, 32/. 

Bain, 367, 395, 411 

Baldwin, J. M ., 5, 271, 411 

Barker, 35, 113, 119 

Beats, tonal, physical basis of, 159/.; in 
dissonance, 159, 165 

Beauchamp, Sally, case of, 454 

Beethoven, auditory imagery in, 267 

Behavior, and consciousness. Chapter 
XVIII, 397-418; 54, 276, 403; observa- 
tion of, as a method in psychology, 3, 7, 
10; and attention, 81 ^.; and affection, 
364/-, 370; in emotion, 377 ff-, 384/-; 
native and acquired, 397; forms of, 
398 ,ff. ; volitional activity in, 401 _ff. 

Belief, judgment as, 323 /., 329 

Berkeley, 219 

Bethe, 34 

Binocular rivalry, 71 /. 

Binocular vision, 107, 210 f. 

Black, as a sensation, 109, 178 /.; in 
Helmholtz theory, 191; in Hering 
theory, 192; see Visual sensations 

Blind, imagery in, 270, 272 

BUnd spot, 170 

Bodily expression, see Behavior 

Bodily sensations, see Organic and Kinaes- 
thetic sensations 

Book, 353 

Bourne, Ansel, case of, 454 

Brain, see Nervous system 

Brain areas. Figs. 28, 29, 30; cutaneous, 
47, 120; somaesthetic, 120/.; pain, 121; 
kinaesthetic, 47, 121; olfactory, 48, 130; 
gu^atory, 48, 138; auditory, 48, 152; 
visual, 44, 48, 172/.; motor, 48; motor 
speech, 48; sensory speech, 50; visual 
for written language, 51; association, 
49/., 69, 242, 354/.; in attention, 67/., 
69; in perception, 201; in imagination, 
239; in reasoning, 354; in affection, 366, 
368 

Brain centres, see Brain areas 

Breese, 72 

Brightness sensations, see Visual sensa- 
tions 

Broca's centre, Fig. 30, 50 /. 



INDEX 



473 



Calkins, 270 

Calm, as affection, 359; cognitive ele- 
ments in, 360 

Cause and effect, relation of, in associa- 
tion, 280/., 287; in judgment, 332 

Cerebral hemispheres, Figs. 6, 7, 8, 9, 19, 
26, 27; see Nervous system 

Cerebral nerves, see Cranial nerves 

Character, and association, 278; and 
imagery, 276; and the will, 416, 429 

Chemical stimuli, 92, 131, 138 

Child psychology, 2, 10 

Children, mimetic movements in, 390; 
unco-ordinated random reactions in, 
398; trial and error learning in, 406; 
conscious control of behavior, 412; in- 
hibition and impulse in, 414; develop- 
ment of attention in, 59, 65 ; inattention 
in, 67; development of perception in, 
77, 204 /., 321; definition by, 302; 
sensory recognition and n^emory in, 
246; concrete imagery in, 272; forma- 
tion of association in, 277; falsification 
of testimony in, 259, 289; meaning and 
reaction, 204/., 302, 335, 417; develop- 
ment of concept and judgment, 335 /.; 
origin and growth of self, 435 /., 438; 
functioning of frontal lobes and atten- 
tion, 69; elasticity of lens in, 171 

Chromassthesia, 271 

Ciaccio, 113 

Circulatory sensations, see Organic sensa- 
tions 

Clearness, as a characteristic of attention. 
Si S-1 65; in shifting of attention, 72; 
as an attribute of sensation, 105 

Cochlea, 144 J".; Figs. 49, 50 

Cochlear fibres, distribution, 45, 152; 
Fig. 24 

Cognition, reference of consciousness in, 
356; sensation as fundamental content 
in, 87, IIS, 351; judgment as funda- 
mental activity in, 329, 336; and affec- 
tion, 356 S; 361 /., 364; and feeUng, 
329, 370, 372 /.; and emotion, 374, 
377 #•, 383; and sentiment, 375 

Cold, sensation of, 108, 124; adaptation 
in, 96, 127; paradoxical sensation of, 
125 /.; see Cutaneous sensation 

Color, sensations, see Visual sensations 

Color-blindness, P89/., 192 

Color contrast, 186 /.; in Hering theory, 
193 



Color mixtures, 183 /.; in Helmholtz 
theory, 192; in Ladd-Franklin theory, 
195 
Color pyramid, 182; Fig. 59 
Color zones, 188; Fig. 60; in color-blind- 
ness, 189; Fig. 61; in Young Helmholtz 
theory, 192; in Hering theory, 193; in 
Ladd-Franklin theory, 194 
Combination tones, 160/. 
Common sensation, pain as, 123 
Comparative psychology, as method, 6 
Comparison, in formation of concept, 302; 

judgment as, 236, 329, 332 
Compensation in sensation, olfactory, 135; 

gustatory, 141 
Complementary colors, 181, 184; in Helm- 
holtz theory, 191; in Hering theory, 
192; in Ladd-Franklin theory, 195 
Complexes, suppressed emotional, 295./., 

445, 449, 461 /. 
Complexes in sensation, 143; in tastfr 

136 
Complication experiment, 79 
Complication in perception, 203, 279 
Compound tones, see Overtones 
Comprehension, 340; see Inference 
Conation, as an aspect of consciousness, 

419^.; in process of attention, 58, 84 
Concentration, as method in memorizing, 

253 
Concept, Chapter XIII, 299-320; nature 
of the, 301, 305 J'.; development of the, 
205, 266, 302, 309 S; 335 /•; and per- 
ception, 203, 205, 300, 309; imagery in, 
274, 26s /., 305 /., 312; meaning in, 
274, 307/., 312; intension and extension 
of, 308; psychological and scientific, 
303; general and individual, 304; and 
creative imagination, 311; and judg- 
ment, 2,iS, 338; and inference, 341; and 
language, 312/. 
Conductivity in nerve-tissue, 3g 
Consciousness, ultimate nature of, i, 10 
f.\ spiritualistic hypothesis of, 10 f.; 
materialistic hypothesis of, 10 S-'> 
subject-object nature of, 12 ^., 55 /., 
425; theory of origin of, 410, 435; as a 
factor in evolution, 369 /., 410 /.; 
function of, 64, 75, 205, 234, 259, 275, 
368 /., 397, 404; observation of, 7 f.; 
elements in, 87, 352 /., 356 /., 420 /.; 
and action, 54, 75 /., 370, 398/., 412 
jf., 424 /.; and attention, 53 f.; in 
learning, 403 f.; determining teaden- 



474 



INDEX 



cies in, s, 424^7.; organization of, in the 
self, 17/., 432^.; and the nervous sys- 
tem, 5, 14/., 21/., 283, 455 

Consonance, 162^. 

Contiguity, principle of, in association, 
281, 283/. 

Contrast, relation of, in association, 280, 
283, 287 

Contrast in sensation, olfactory, 135; 
gustatory, 141; visual, 186/. 

Convergence, 168; sensations of, 221 

Cope, 411 

Cortical centres, see Brain areas 

Cramming, in learning, 255 

Cranial nerves, 30; Fig. 9 

Crime, association tests in detection of, 
295 

Curiosity, 384 

Cutaneous sensations, Chapter V, 118- 
129; classification of, 108; end-organs 
of, 118^.; punctiform character of end- 
organs, 122 Jf.; evolution of sense- 
organs, 91; brain areas of, 47, 120/.; 
adaptation in, 96, 124, 127; after-images 
in, 95, 123; and subcutaneous sensa- 
tions, 128/.; and taste sensations, 136, 
142, 143; in perception of heat, 125/. 

Czermak, 145 



Darwin, 387 /. 

Day-dreaming, imagination in, 264/.; 

associative recall in, 259 
Decision, in will, 422 
Deduction, 345 ff. 
DeUrium tremens, 211 
Delusions, 459 
Dementia, 456 
Dementia prascox, 458 
Depression, as attitude in insanity, 458 
De Quincey, Thomas, 211 
Descriptive psychology, 4 
Dexter, 406 
Dewey, 343, 344 
Dichromasia, 349 
Difference-threshold, intensity of stimuli, 

100; in pitch, 156 
Difference tones, 160 
Dissociation, 446 f. 
Dissonance, 159, 162 _ff. 
Dizziness, sensation of, 115, 117 
Dogiel, 120 

Double personaHty, 453 
Drainage theory of association, 297 /. 



Dreams, nature of consciousness in, 444 
/.; and hallucinations, 211; as symbols 
of suppressed wishes, 296, 444 /. 

Duration, attribute of sensation, 105; in 
time perception, 230 ff.; and affection, 
361/. 

Dynamogenesis, law of, 412^. 

Edinger, 28, 29, 47 

Educational psychology, 2 

Effort, in attention, 54, 58, 83, 61, 66; 
feeling of, in will, 425 

Egger, Victor, 272 

Ego, 12 ff., 55; in theory of will, 420; as 
directive tendency, 424 /.; as unifying 
principle, 433, 443 

Eigenlicht, 176 

Electrical stimuli, 92, 138, 176 

Emotions, Chapter XVII, 377-396; na- 
ture of, 374 f., 391; conditions of, 391/.; 
significance of, 394 /.; feeling in, 374, 
377; affective element in, 384; cognitive 
element in, 377 ^.; organic and kinaes- 
thetic sensations in, no/., 377 ff., 383; 
and memory, 395 /.; instinctive reac- 
tions in, 317, 377 ff., 384 ff.; classifica- 
tions of, 395; and the self, 441 /.; and 
passion, 376; disturbances of, in insan- 
ity, 458; James-Lange theory of, 377 ff. 

Epicritic sensations, 129 

Equilibrium, sense of, 115 /.; in deaf- 
mutes, 116 

Ethical experience, 373, 376 

Ethnic psychology, 3 

Evaluation, judgment as, 327 

Excitement, as affection, 359; as attitude 
in insanity, 458 

Experimentation, as method in psychol- 
ogy, 4, 6; in attention, 66, 76, 78_^., 80; 
in kinaesthetic sensations, 113 ff.; in 
cutaneous sensations, 106, 121 ff., 127, 
215, 217; in olfactory sensations, 134 
/.; in gustatory sensations, 138 ff.; in 
auditory sensations, 155, 157, 159 /.; 
in visual sensations, 94/., 184 jf., 188/.; 
in perception, 200, 207 ; in tactile space, 
215 jf-; in visual space, 219 ff.; in 
auditory space, 228/.; in time, 231 ff.; 
in imagination, 269; in association, 
290^., 449; in memory, 253 /.; in af- 
fection, 364 /.; in organic reactions in 
emotion, 381, 387; in trial-and-error 
method in learning, 405 

Extension, in concept, 308 /. 



INDEX 



475 



Extensity, as an attribute of sensation, 
103 /.; of auditory sensations, 161 /., 
216; of visual sensations, 215, 218; in 
space perception, 213 J". 

Facial expressions, 389 /. 

Facilitation, 68 

Fancy, 261, 264 

Far-sightedness, 172 

Fatigue, and attention, 67; memory in, 

257 

Fear, 384/., 392/.; organic sensations in, 
no 

Fechner, loi 

Feeble-mindedness, 456 

Feelings, Chapter XVI, 356-376; nature 
of, 356, 370/.; affection and cognition 
in, 356, 370^.; and organic sensations, 
no /., 370, 372; and kinaesthetic sen- 
sations, 417; classification of, 371 /.; 
in attention and interest, 54 /., 84 /.; 
in intermittent sensations, 165; in con- 
sonance and dissonance, 164 /.; of 
familiarity, 204, 245 /.; and memory, 
25s; and judgment, 328; in trial-and- 
error method, 406 /.; in mood and 
temperament, 373 /.; in emotion, 374 
/.; in sentiments, 375; and the self, 
441/. 

Fiat, 422 

Flechsig, 49, 50 

Flechsig centres, 49, 354 

Fluctuation of attention, 70 ff. 

Folk psychology, 3 

Forgetting, 254/., 296 

Foveal vision, 168/., 175, 180 

Franz, 129 

Frequency, in association, 243, 285 

Freud, 295, 296, 445, 461 

Frey, von, 126 

Friendship, 375 

Fry, 22g 

Functional psychology, 5 

Gallon, 267, 269, 271, 273 
Galton whistle, 155 
Galvanometer, 365 
Gegenbaur, 39 
Generalization, 302 ff. 
Generic image, 306 /. 
Genetic psychology, 2, 4 
Gesture language, 314 #. 
Global method, 253 



Gray, in Hering theory, 193; in Ladd- 
Franklin theory, 194/. 

Greejf, i6g 

Grief, emotion of, 394 

Gustatory sensations. Chapter VI, 136- 
143; classification of, 109, 139; end- 
organ of, 137, 139; brain areas of, 48, 
130; retardation of, 140; imagery of, 
268; affection and, 361; and mimetic 
movements in emotion, 389 /. 

Habit, nature of, 400 /.; and volitional 
action, 401^.; law of, in recall, 243; as 
organic memory, 248 /.; imagery and, 
275; and association, 279; neural basis 
of, 279, 400 

Hallucinations, and perception, 203, 210 
_ff.; neural basis of, 212; in insanity, 459 

Hardesly, 151 

Haycrafl, 132 

Hearing, see Auditory sensations 

Heat, perception oi, 125 Jf. 

Hegel, 358 

HelmhoUz, 150, 155, 165, 171, 191, 338, 339 

Hemianopsia, 174 

Hensen, 151 

Hering, 192, 224 

Hering color theory, iq2 _ff. 

Hippocrates, 455 

Hobhouse, 404 

Howell, 44, 145 

Human adult psychology, 2 

Hume, 336, 439 

Hunger, 92, 109, no; as a feeling, 370 

Hyperaesthesia, in hypnosis, 451; in hys- 
teria, 461 

Hypermnesia, 258 

Hyperopia, 172 

Hypnosis, 450 /. ; hallucinations in, 211; 
mental blindness in, 447; and will, 452 
/.; suggestion in, 450 J". 

Hypothesis, in science, n 

Hysteria, 295, 445, 448, 461; association 
method in, 295; psychoanalysis in, 
296, 445, 461; mental blindness and 
sensory anaesthesia, 447; automatic 
writing in, 448; somnambulism in, 440; 
suggestion in, 461 

Idea, 274 

Ideals, 376 

Ideogram, 315 

Ideo-motor reactions, 398, 401 

Idiot, 457 



476 



INDEX 



Illusions, and perception, 203; and hal- 
lucinations, 203, 210; causes of, 206^.; 
of space, 222 Jf., 225 Jf.; of movement, 
207 /.; in memory, 258; neural basis of, 
212 

Imageless thought, 351 /.; and volition, 
424 

Imagery, 238/.; types of, 266 #.; concrete 
and symbolic, 271 /., 305, 312 ff.; in- 
dividual differences in, 267, 272; in 
synaesthesia, 270; in sleep and dreams, 
444 /.; in concept, 305 /.; in thinking, 
29Q, 320, 351 f.; in consciousness of re- 
lation, 351 /., 353; in volitional action, 

403 

Imagination, Chapter XI, 260-276; and 
sensation, 238, 262, 266, 274; and per- 
ception, 203, 238/., 262, 268, 274; and 
memory, 240, 260; and feeling, 370; and 
affection, 363, 366; and thinking, 299, 
351 /.; reproductive, 240, 261 Jf.; pro- 
ductive, 261 ff.) development of, 272/.; 
training of, 274/.; and behavior, 64, 275 
/.; function of, 64, 234, 275; neural basis 
of, 50, 238/. 

Imbecile, 457 

Imitation, 384; in gesture language, 314; 
in early writing, 315; in spoken lan- 
guage, 316 

Impulse, motor, in consciousness, 82, 276, 
296, 402, 412 _^., 419 

Inattention, 67 

Indifference, as attitude in insanity, 458 

Individual differences, in olfactory sen- 
sations, 134; in taste, 142; in pitch dis- 
crimination, 156; in retention, 241; in 
memory, 249/.; in imagery types, 272, 
267; in temperament, 374; in suggesti- 
bility, 452 

Individual psychology, 2 

Induction, 345 /. 

Inference, 338 f.; inductive and deduc- 
tive, 345 ff.; and perception, 339; and 
concept, 341; and judgment, 334, 338, 
340; in thinking process, 3cx3, 338/., 344 

Inhibition, in action of nervous centres, 
68; retroactive, 282; and affection, 367; 
and impulse, 414; defective in impulsive 
will, 428; in hypnosis, 451 jf. 

Innervation, feeling of, 426 

Insanity, 455; classification of, 455; and 
hallucinations, 210; association tests in, 
291, 295; psychoanalysis, 295/., 445 
^., 461; neural basis of, 455, 462 



Inspiration, and imagination, 264 

Instinctive reactions, 397 /.; theories of 
origin, 410/.; in emotion, 378, 384^.; 
in development of self, 436; neural basis 
of, 375, 386 /. 

Integration, principle of, 280 

Intension, of concepts, 308 

Intensity, as attribute of sensation, 98 f. \ 
distinguished from vividness, 105; of 
auditory sensations, 161, 229; of visual 
sensations, 180; and affection, 360 /., 
368; and pain, 99, 362; and attention, 
65; Weber's law in, loi /. 

Intention or purpose, in volitional activ- 
ity, 402 

Interest, and attention, 54/., 59/., 84/.; 
native and acquired, 85 ; feeling element 
in, 54/., 84/.; and memory, 255; and 
association, 281; and the self, 427, 440 

Interjectional theory, of language origin, 
318 

Intertone, 160 

Introspection, as scientific observation, 
7^.; in attention, 56, 82/.; in sensation, 
87 /•> 97. 102, 104, III, 113, IIS, 117. 
118, 124, 136, 144, IS4, 157; in per- 
ception, 87/., 210; in affection and feel- 
ing, 357, 372; in judgment, 322, 326, 
336; in consciousness of relation, 336; 
in imageless thought, 352/.; in volition, 
420, 423, 425; in sleep, 444 

Invention, and imagination, 261 /. 

Involuntary attention, 60 

Involuntary movements, in attention, 8* : 
in affection, 364 /. 

Irene, case of, 450 

Irritability of nerve- tissue, 39, 89 

James, 12, 87, 104, 173, 208, 210, 214, 216, 
219, 240, 249, 250, 252, 265, 267, 286, 
292, 300, 336, 350, 377, 379, 383, 384, 
386, 410, 422, 424, 426, 427, 428, 434, 
437, 454 

James-Lange theory of emotions, 377 ^. 

Janet, 450 

J as trow, 257 

Jastrow's illusion of area, 225, 226 

Jost's law, 282 

Joy, emotion of, 393 

Judd, 47, 286 

Judgment, Chapter XIV, 321-337; nature 
of, 321 _ff.; in the thinking process, 
300, 335 1-; as apperception, 322, 324; 
as belief, 323, 329; as ascription of 



INDEX 



477 



meaning, 324, 329; as comparison, 326, 
329, 332; as evaluation, 327, 330; de- 
velopment of, 335 ; analysis and syn- 
thesis in, :iss /.; logical and psycho- 
logical, 321 ff., 330 ff.; kinds of, 331 /.; 
and perception, 203, 204, 321 /., 325, 
327, 332, 334. 337; and recognition, 204; 
and feeling, 328; and association, 324, 
328; and concept, 335, 338; and infer- 
ence, 334, 337, 338/., 340 
hmg, 295, 296 

Kant, 322, 323, 434 

Kiesow, 140 

Kinaesthetic sensations. Chapter V, 112- 
117; classification of, 108; observation 
of, 113; stimuli of, 112, 116; sense- 
organs of, 112, 116, 128; brain areas 
of, 47, 121, 152; as eflFort in attention 
and will, 54, 55, 58, 82 /., 425; in in- 
nervation, 426; in touch, 118; in space 
perception, 114/., 213 ff.; local sign in, 
214^.; in locomotor ataxia, 401, 423; 
in time perception, 232 /.; imagery of, 
267^., 272, 421/.; as cues in habit, 401; 
in consciousness of relation, 351; 
imagery of, in voHtional action, 421 /.; 
in feeling, 360, 416/.; in emotion, 374, 
377 jff; 383, 417; in consciousness of self, 
18, 112, 42-6, 435, 437 

Kolliker, 33 

Krause, end-organ of, Fig. 43, 120 

Ladd and Woodworth, 28, 29, 31, 34, 35, 39, 
46, 102, 103, 113, 117, 118, 119, 150, 
171, 209, 298. 

Ladd-Franklin theory of color vision, 
I94J"- 

Lange, 377 

Language, and introspective method, 8/.; 
function of, 313; development of, 314; 
origin of spoken, 316; imagery in, 272, 
312 ff.; and concept, 312; and judgment, 
321 ff.; and thought, 320; in feeble- 
minded, 457; brain centres involved 
in, SI 

Lapsed intelligence theory, 411 

Latent period, in perception, 79, 200 

Learning, and memory, 253 /., 255; 
through trial and error, 405 ff., 420; 
through conscious control, 403 ff., 420 /. ; 
in animals, 405 

Lehmann, 368 

Linnmis, 132 



Lipps, 227 

Lipps's parallels, 224 

Literature, and imagination, 261 /.; and 

feeling, 371 
Local sign, 106, 122, 213 X 
Localization, in space perception, 216 ff., 

228/. 
Localization, of function in the brain, 47 ff. 
Locke, 12, 240, 306, 342, 443 
Locomotor ataxia, 401, 423 
Logic, formal, in practical thinking, 34~5 

ff.; in formation of concept, 302 /.; in 

judgment, 321 ff., 330/.; in inference, 

345 ff- ; syllogism in, 349 
Logical memories, 250 /. 
Logical present, 233 
Love, as sentiment and emotion, 375 

McDougall, 297 

Mania, 458 

Masson's disc. Fig. 36, 72 _^. 

Materialistic hypothesis of consciousness, 
10/. 

Mathematics and imagination, 261 /. 

Meaning, consciousness of, in perception, 
203 /., 321, 325, 339; and image, 266, 
274, 305, 307, 312, 353; in concept, 307 
ff.; in judgment, 324/., 329 J".; language 
and, 312 ff. 

Measurement, as method in psychology, 
4, 8/.; in attention, 66, 76, 78/., 80; 
in intensity of sensation, ggff., 122; in 
two-point threshold, 106, 122; in ol- 
factory sensations, 134; limits of tonal 
range, 155; tonal discrimination, 156; 
fields of retinal color zones, 188; of 
association time, 292; of learning and 
memory, 254; see Experimentation 

Mechanical stimuli, 92, 138, 152/., 176 

Meissner's corpuscle, 91, 119, Fig. 41 

Melancholia, 458 

Memory, organic, 248/. 

Memory, Chapter X, 238-259; nature of, 
240 jf.; function of, 259; and imagina- 
tion, 238.^., 260; stages, 241; retention, 
241, 252; recall, 241 //., 250 /., 253; 
recognition, 241, 24S_^., 258, 260; logical 
and rote, 250/.; methods of memoriz- 
ing, 253 /.; and forgetting, 254 ff.; 
training of, 252; individual difference 
in, 241, 249/.; defects of, 257/.; atten- 
tion and, 81, 253 /.; and affection, 363 
/.; and feeling, 255, 370; and emotions, 
395 /•; of time periods, 236; and self, 



478 



INDEX 



437; neural basis of, 50, 238/., 241,- 252, 

256 
Mendelejefif's groups, and olfactory 

stimuli, 131 
Mental blindness, 51, 201, 447 
Mental deafness, 51, 152, 201, 447 
Meyer experiment, 187 
Meynert, 368 
Michotte, 423 

Mimetic movements, in emotion, 390 
Mind, 16/., S5l; 241 
Mind- readers, 82, 415 
Modality in sensation, 98 
Mood, 373 
More, L. T., 229 
Moron, 457 
Mosso, 387 
Motor activity, and consciousness, 402 

#., 412/., 416/., 422 
Motor aphasia, 51 

Motor areas in cortex, 48, Figs. 28, 29, 30 
Motor attitude, in consciousness of re- 
lation, 351 
Motor tracts, 40/., Figs. 18, 21 
Movement, compensatory, in disturbed 

equilibrium, 115 
Movement, sensations of, see Kinacsthetic 

sensations 
Miiller-Lyer circle, 225, 226 
Miiller-Lyer illusion, 209, 226/. 
Miinsterberg, 105, 289, 295, 368, 382, 

424 

Muscular sensations, see Kinsesthetic sen- 
sations 

Musical tones, 156, 162^. 

Myers, 229 

Myopia, 172 

Nausea, 109, no, 133 

Near-sightedness, 172 

Nerve-cell, 32 Jf. 

Nerve impulse, 36 J'., 89 

Nervous system. Chapter II, 21-52; and 
consciousness, 5, 14/., 21/., 283, 45s; 
development of, 22 _ff.; gross structure 
of, 2b ff.; neurones and connections in, 
32^.; localization of function in, 47 ff.; 
organic memory in, 248 /.; law of re- 
gression in, 256; see Neural basis 

Neural basis of, consciousness, 5, 14 /., 
2r/., 283, 44S; attention, 67/., 74/., 
298; sensation, 88 _ff., 98 /., 104; or- 
ganic sensations, 91 /., in; kinassthetic 
sensations, 47, 112, 116, 121, 128, 152; 



cutaneous sensations, 47, 118/., 120/., 
123/., J26 Jf.; olfactory, 48, 130, 134; 
gustatory, 48, 130, 134, 137/., 139/-; 
auditory, 48, 144^., 152/., 162; visual, 
44, 48, 166/., 172/., 176/., 188/.; 
perception, 48, 68, 201 /., 212, 239; il- 
lusion, 212; hallucination, 212; associ- 
ation, 49 /., 69, 242, 283, 285, 296 Jf., 
354/.; memory, 50, 238/., 241, 252, 256; 
retention, 241, 252, 256; recall, 241 /.; 
imagination, 50, 238/.; reasoning, 354; 
affection, 366/., 382; impulse, 415, 418; 
instinctive reactions, 375, 386/.; habit, 
279, 400; insanity, 455, 462 

Neurasthenia, 295, 460 

Neurology, 6 

Neurone, 3 2 _^. 

Noises, 109, 144, 154; see Auditory sensa- 
tions 

Non-voluntary attention, 59; and inter- 
est, 85 

Number forms, 271 

Nystagmus, 190 

Observation, method in psychology, 7 ff.; 
see Introspection, Behavior, Experimen- 
tation 

Obsessions, 460 

Octave, in musical scale, 162; as con- 
sonant interval, 165 

Oehrn, 66 

Oehrwall, 140 

Ogden, 424 

Olfactory area in cortex, 48, 130 

Olfactory sensations. Chapter VI, 130- 
136; classification of, 109, 132; stimulus 
of, 130/.; end-organ of, 130, 134; brain 
centres, 48, 130; adaptation, 96, 134; 
threshold, 133; extensity attribute in, 
104, 215; fusions, contrast, compensa- 
tion, 13s; and gustatory sensations, 
136, 143; and kinesthetic sensations, 
416; and imagery of, 268; and affection, 
361; and feeling, 135 

Onomatopoetic tendency in language, 
273, 3i6#. 

Ontogenesis, 4 

Opium, effect of, in hallucinations, 211; 
on imagination, 265 

Optic chiasma, 44, 172/. 

Optic disc, 170 

Optic nerve, 30, 44, 169, 172 ff. 

Organ of Corti, 148^., Fig. 51 

Organic memory, 248 /. 



INDEX 



479 



Organic sensations, Chapter V, 110-112; 
classification of, 108, no/.; stimuli of, 
91/., in; end-organs of, in; localiza- 
tion of, 112; in time perception, 231, 
233, 23s /.; and affection, 258, 360; in 
feeling and emotion, no /., 370, 372 
/•. 377/-. 383; in sleep, 443; and self, 
18, 112, 435, 437 

Overtones, physical basis of, 157; in 
timbre, 158; in consonance and dis- 
sonance, 165; as aid in localization of 
sound, 229 

Pacinian corpuscles, 112, 120 

Pain-sensations, 122/.; distinguished from 
affection, 124, 362; and feeling, 370; 
and intensity of sensations, gg, 362 

Paradoxical sensation of cold, 125 

Parallax, 222 

Paramnesia, 258 

Paranoia, 459 

Partial recall, 251, 288/. 

Partial tones, see Overtones 

Passion, 376 

Passive attention, 61 

Pathognomic theory, of origin of spoken 
language, 318 

Perception, Chapter IX, 197-237; and 
sensation, 197 _ff., 204; complication in, 
203, 279; recognition in, 200, 203 /., 
246 /., 321, 337; meaning in, 197 ff., 
203 /., 321, 325, 339; illusions in, 203, 
206 f., 212; hallucinations and, 203, 
210 _^.; function of, 205; development 
of, 77, 202, 204/., 321; units of, in at- 
tention, 77; latent period in, 79, 200; 
and imagination, 203, 238 /., 262, 266 
/., 268/., 274; and association, 278/.; 
and concept, 203, 205, 300, 309; and 
judgment, 203/., 321 /., 325, 327, 332, 
334. 337; and inference, 338 /.; and 
thinking, 299/.; and aSection, 363; in 
emotion, 374, 383; and motor reaction, 
202, 204, 302, 417; and the self, 440; 
neural basis of, 48, 68, 201/., 212, 239; 
of tactual space, 103 /., 106, 122, 213 
^. ; of visual space, 103/., 106, 114, 172, 
21 2 _^.; of auditory space, 103/., 161 /., 
216, 228/.; of time, 105, 230 _^. 

Perimeter, 188 

Perspective, in visual space perception, 
221/. 

Phosphenes, 176 

Photic stimuli, 92, 176 



Phjdogenesis, 4 

Physiological basis, see Neural basis 

Physiological psychology, 5 

Physiological reactions, 398 

Physiological stimuli, in organic sensa- 
tions, 91, 108, in; in vision, 176 

Physiological zero in temperature sensa- 
tions, 124^. 

Pillshury, 82, 199, 334, 120 

Play, 384 

Pleasantness, see Affection 

Plethysmograph, 364 

Pneumograph, 364 

Poggendorff figure, 225 

Prejudice, 342 

Presbyopia, 171 

Pressure sensations, see Cutaneous sensa- 
tions 

Primitive peoples, language and writing, 
315/- 

Prince, 454 

Projection, in space perception, 216 f., 
228/. 

Protopathic sensations, 128 

Psychic blindness, 51, 201, 447 

Psychical present, 232/. 

Psychoanalysis, 295, 445, 449, 461 

Psychology, definition of, i; fields of, 2; 
methods of, 2; scientific method in, 7 
f.; data of, differentiated, i, 10 ff., 13 
Jf; 92/, 322, 419, 425, 429/-, 434 

Psychophysics, 6 

Pupillary reflex, 170 

Purkinje phenomenon, 180, 194 

Purkinje's network, 168 

Quain, 118, 138 

Quality, as an attribute of sensation, 97 

/.; and affection, 360, 361 
Quincke's tubes, 160 

Race psychology, 3 

Ranvier, 118 

Raphael, hallucinations in, 211 /. 

Rayleigh, 229 

Reaction, motor, native, and acquired, 
397 #■. 410 /.; co-ordinated and unco- 
ordinated, 397 #.; and attention, 75/., 
So Jf.; and meaning, 202, 204, 302, 335, 
351, 417; in appetition and aversion, 
369; instinctive, in emotion, 377 Jf., 
384/.; vocal language as, 317/. 

Reaction time, in attention, 80; in associ- 
ation tests, 293 



48o 



INDEX 



Reading, nature of perception in, 77 

Reasoning, Chapter XV, 338-355; re- 
flective thinking in, 342 Jff.; inductive 
and deductive inference in, 345 f.; 
formal logic and inference in, 340 /. ; 
imagery and mental content in, 351 ^.; 
neural basis of, 354 /. 

Recall, factors determining, 81, 243 /., 
285; laws of association in, 283 f.; 
spontaneous, 243; control of, 244; as- 
sociation by contiguity as total recall, 
288/.; association by similarity as par- 
tial recall, 288 /. ; desultory memory, 
250; logical memory, 250/.; in associa- 
tion tests, 290 _^.; as method in memo- 
rizing, 253; neural basis of, 241 /. 

Recapitulation, 4 

Recency, 243, 282, 285 

Recognition, feeling of familiarity in, 204, 
245/., 247, 258; function of, 247/.; in 
perception, 200, 203/., 246/., 321, 337; 
in memory, 241, 245 ff., 258, 260; as 
consciousness of relation, 337; and the 
self, 435 ; in paramnesia, 258 

Reed, 12 

Reflective thought, see Reasoning 

Reflex theory of instinct, 411 /. 

Reflexes, 397 f.; compensatory, 115; 
pupillary, 170 

Regression, law of, 256 

Relationship, consciousness of, 17, 299 
f-> 336/.; implicit in jjerception, 299/., 
321, 337; explicit in judgment, 321, 330, 
332/., 334/-; consciousness of meaning 
as, 308; context of consciousness in, 
351 /.; affection and, 358 

Relativity, theory of, 103 

Relaxation, as affection, 359; cognitive 
elements in, 360 

Religious experience, feelings, 373; senti- 
ments, 376 

Repetition, as method in memorizing, 253; 
and association, 282 

Respiratory sensations, no; see Organic 
sensations 

Retardation of sensation, 94; in pressure 
and pain, 123; in cold and warm, 125; 
in salt and bitter, 140 

Retention, in memory, 241, 252; as or- 
ganic memory, 248; neural basis of, 
241, 252, 256 

Retina, 166, 168/., Fig. 54; color zones of, 
188; corresponding points on, 107, 
219/. 



Retroactive inhibition, 282 

Retzius, 118, 150, 138 

Reverie, 264 

Rhythm, organic, sensations of, in time 

perception, 233 
Ribol, 81 
Rivalry, in olfactory sensations, 135; in 

gustatory sensations, 141; binocular, 

71/. 
Rivers and Head, 128 
Rods and cones, 166, 168; distribution, 

169; differentiation of function, 175, 

194; in total color-bHndness, 190 
Rote memory, 251 
Ruger, 40s 
Rutherford, 151 

Saturation of colors, 181; in Helmholtz 
theory, 191; in Hering theory, 193 

S chafer, 34, 132 

Schumann, 326 

Schwalbe, 31 

Science and imagination, 261 /. 

Seguin, 173 

Self, Chapter XX, 432-462; nature oif, 
17/-. 434 #•. 442; egoistic reference of, 
438; dynamic aspect of, 434/., 439/.; 
continuity of, 432 /., 443, 446; origin 
and growth of, 435/., 438; social factor 
in, 436, 437, 438/.; contents of, 437; 
kinaesthetic and organic sensations in, 
18, 112, 417, 435, 437; memory in, 437; 
attention and, 440; sensation and, 439; 
perception and, 440; feeUng and, 441; 
interest and, 440 /. ; suggestion and, 
453; will and, 425, 427 /., 442; con- 
flicts in, 428; disturbances of, 446; dis- 
sociations in, 446 ff.; dreams and, 444 
/.; sleep and, 443 

Semicircular canals, sensations from, 115; 
see Kinaesthetic sensations 

Seneca, memory in, 258 

Sensation, Chapter IV, 87-109; as an ele- 
ment of consciousness, 87, 115, 351; 
definition of, 87, 204; pure, 88, 204, 
300; attributes of, 97 ff., 105 /., 357 /.; 
modahty in, 98; quahty, 97 /.; inten- 
sity, 98 J'.; duration, 105, 230 #.; ex- 
tensity, 103/., 2i4.#.; classification of, 
107 Jf.; retardation, 94; threshold, 99 
/.; adaptation, 96; after-image, 94 /.; 
complexes in, 143; local sign in, 106/., 
213 J'.; and perception, 115, 197 J"., 204; 
and imagination, 238, 262, 266 ff.; 



INDEX 



481 



imageless thought, 351; and conscious- 
ness of relation, 351; and affection, 356 
/•, 359. 361 /., 366, 367/-; and the self, 
439; neural basis of, 88 ff., 98, 104 

Sense-organs, function of, 88 /.; evolu- 
tion of, 90 /., 135, 194; stimuli of, 8g, 
gif., Ill, 112, 116, 124/., 130/., 138, 

• 152 /., 176 /.; range of response, 131, 
ISS, 177; latent period of, 94, 123, 125, 
140; inertia in, 94/., 99/., 122/., 133, 
142, 161, 185 /.; adaptation in, 96 /., 
124, 127, 134, 141, 175, 180, 184 /.; 
accommodation of, in attention, 54, 73 
/., 83, 169 

Sensory aphasia, 51, 152, 201, 447 

Sensory areas in corfex, 47/., 120/., 130, 
152, 172/.; Figs. 28, 29, 30, 58 

Sensory tracts, from skin and muscles, 

43, 120/.; Figs. 18, 22; from olfactory 
cells, 130; from taste-buds, 138; from 
vestibule, 46, 152, Fig. 25; from 
cochlea, 46, 152, Fig. 24; from retina, 

44. 172, Figs. 23, 54, 58 
Sentiments, 375 

Sexual sensations, see Organic sensations 

Shepard, 382 

Sherrington, 381 

Sidis, 454 

Similarity, law of, in association, 285 .#.; 
in reMoning, 350 

Skill, acts of, organic memory in, 248; 
motor connections in, 279; method of 
learning, 406 /. 

Sleep, 443 /. 

Smell sensations, see Olfactory sensations 

Sobotta-McMurrich, 28 

Social factors, in self, 436, 437, 438/. 

Social experience, 373, 376 

Social psychology, 2 

Someesthetic area, 120/., Fig. 28 

Somnambulism, 449 /. 

Sonometer, 157 

Soul, I, IS 

Space perception, nature of, 212 /.; 
theories of, 213/.; -synthesis of sensa- 
tions in, 103 /., 106, 114 /., 122, 172, 
213^., 219 J"., 225/.; illusions in, 206/., 
222^.; see Auditory, Visual, and Tac- 
tual space perception 

Specific energy of nerves, 90 

Specious present, 232 /. 

Spectrum, physical nature of, 176 /. ; 
sensation qualities in, 179, 182; inten- 
sity of, and brightness, 180; saturation 



of colors in, 181; to light and dark 
adapted eye, 180/.; to color-blind, 189, 
190 

Speech centres, 50/.; see Language 

Spencer, 385, 386, 411 

Spencer-Bain theory of origin of con- 
sciousness, 411 

Sphygmograph, 364 

Spinal cord, 23, 30, 40 J'., 129, 401; Figs. 
5, 10, 18, 20, 21, 22; see Nervous sys- 
tem 

Spiritualistic hypothesis of consciousness, 
10 i". 

Spontaneous attention, 59, 85 

Starr, 46 

Static sensations, see Kinesthetic sensa- 
tions 

Steinlhal, 292 

Stereoscopic vision, 107, 219X; binocular 
rivalry in, 71 

Stern, 290 

Stimuli, of sense-organs, nature of, gi Jf.; 
classification of, 92; adequate and in- 
adequate, 89, 92, 176; intensity of, and 
sensation, ggjf., 122, 133, 142, 161, 180; 
duration of, and sensation, 94 Jf., 1 23 
/., 127, 134, 142, 184/.; classification of 
sensations according to, 107 

Stout, 251, 315, 319 

Strain, as affection, 359; cognitive ele- 
ments in, 360; see Effort 

Strieker, 272 

Stumpf, 164 

Subconsciousness, 57, 296 

Suggestion, in hypnosis, 451 ff.; in hys- 
teria, 461; illusions in memory due to, 
258, 289; individual differences in, 452 

Sully, 206 

Summation tone, 160 

Superstition, 342 

Syllogism, and reasoning, 349 

Sympathetic nervous system, see Auto- 
nomic nervous system 

Sympathetic-resonance theory of hearing, 
150/., ISS, 162 

Synesthesia, 270 /. 

Synapse, 37 

Synthesis, in perception, 88, 197 jff., 321, 
32s; of sensations in space perception, 
172, 21^ Jf.; of sensations in time per- 
ception, 231 ^.; in judgment, 333 /. 

Tachistoscope, 76, 200 

Tactile sense, see Cutaneous sensations. 



482 



INDEX 



Tactual space perception, extensity, 103 
/.; local sign, 106, 122, 214; synthesis 
with kineesthetic and visual sensations, 
212, ff.; illusions in, 206/., 222/. 

Taste sensations, see Gustatory sensations 

Taylor, 315 

Telephone theory of hearing, 151 

Temperament, 373 

Temperature sensations, see Cutaneous 
sensations 

Tendinous sensations, see Kinaesthetic 
sensations 

Tension, as affection, 359 

Testimony, 246, 258 /., 289 

Thermal stimuli, 92, 124/. 

Third dimension, perception of, 218 ff. 

Thirst, 92, 109, no 

Thorndike, 33, 113, 119, 170, 249, 389, 405 

Threshold of sensation, 99 /. ; of pressure 
sensations, 122, 215, 217; of olfactory 
sensations, 133; of gustatory sensa- 
tions, 142; of auditory sensations, 161 

Timbre, 158, 229 

Time perception, 230/.; sensory material 
in, 105, 231^., 23s/.; duration and suc- 
cession in, 231 /.; psychical present in, 
2T,2 f.; measure of, 234^. 

Titchener, 56, 105, 108, in, 115, 117, 118, 
iSS, 182, 351, 353, 359, 360, 367, 411 

Tone, 109, 144, iS5#.; see Auditory sensa- 
tions 

Tone-deafness, 157 

Total recall, 250, 288/. 

Transfer of training, 252 

Trial-and-error method, 297, 405 ff. 

Unpleasantness, and pain-sensation, 124, 
362; see Affection 

Value, judgment of, 328 

Van Gehuchten, 29 

Vestibule, sensations from, 115; distribu- 
tion of fibres from, 45, 152, Fig. 25; see 
Kinaesthetic sensations 

Villiger, 23 

Visual area, 44, 48, 172/., Fig. 29 

Visual purple, 174, 181 

Visual sensations, classification of, 109, 
178/.; stimulus of, 176/.; sense-organ, 



91, 166 X; brain areas, 44, 48, 172 J".; 
intensity in, loi, 180; extensity, 215, 
218; contrast, 186/.; adaptation, 96/., 
175, 180/., 184/.; after-images, 94/., 
185 /.; theories of, 190^.; imagerj' of, 
267 

Visual space perception, extensity, 103 /., 
215; local sign in, 107, 214/.; eye move- 
ments in, 115, 214, 217 J"., 221, 225/.: 
synthesis of cutaneous and visual sen- 
sations in, 172, 21$ Jf.; binocular vision 
in, 107, 2 ig _ff.; association aids in, 221 
/.; development of projection in, 216/.; 
illusions in, 222 _ff. 

Vividness, as attribute of sensation, 105; 
factor in association, 243, 285 

Vocal sound, in language, 317, 319 

Volitional action, 401 _ff., 420 ff. 

Voluntary attention, 60. 85 

Wandering attention, 67 

Ward, 411 

Washburn, 351 

Weber's law, loi /. 

Wernicke's centre, 51 

Whipple, 289, 291 

Will, Chapter XIX, 419-431; nature of, 

421 /.; theories of, 420 /.; content of 

consciousness in, 402/., 420 Jf., 425/.; 

and the self, 427 ^., 442; freedom of, 

429 /. 
Wilson, 229 
Wolff, 358 
Woodworth, 352 
Word-blindness, 51, 201 
Word-deafness, 51, 152, 201, 447 
Word-image, 271/., 305, 320 
Writing, imitative tendency in, 315 
Wundt, 214, 359, 386, 389, 395, 411 

Young-Helmholtz theory of color vision, 
191/- 

Zeno, 391 

Ziehen, 103, 366 

Zola, olfactory imagery in, 268 

Zo liner figure, 224 

Zwaardemaker, 132 



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